Biology Energy Processingcontent.njctl.org/courses/science/biology/energy-processing/energy...A...
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Transcript of Biology Energy Processingcontent.njctl.org/courses/science/biology/energy-processing/energy...A...
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Biology
Energy Processing
wwwnjctlorg
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Vocabulary
glycolysis
aerobic anabolic pathwayanaerobic
Calvin Cycle
chlorophyllcellular respiration
FADH2
fermentation
lactic acid fermentation
metabolism
ATP
NADHcitric acid cycle
electron transport chain
Krebs cycle
electron acceptor
facultative anaerobe
Acetyl CoshyA
ATP synthase
NADPH
catabolic pathway
ethanol fermentation
cyclic energy transport
light dependent reactionslight independent reactions
Click on each word below to go to the definition
4
Vocabulary
pyruvate
oxidation
reductionpyruvate decarboxylation
phosphorylationoxidative phosphorylation
obligate anaerobeobligate aerobe
photosynthesisphotosystem Iphotosystem II
noncyclic energy transport
thylakoid
Click on each word below to go to the definition
5
Energy Processing Unit Topics
middot Metabolism amp ATP
middot Cellular Respiration
Click on the topic to go to that section
middot Fermentation
middot Photosynthesis
6
Chapter 8Metabolism amp ATP
Return toTable ofContents
7
Metabolism is the totality of an organismrsquos chemical reactions
Metabolism is a property of all life
Metabolic Pathways
8
A metabolic pathway begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
Without enzymes metabolic pathways would proceed very slowly
Metabolic Pathways
enzyme 1 enzyme 2 enzyme 3
A B C D
Starting Molecule
Product
Reaction 1 Reaction 3Reaction 2
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
2
Biology
Energy Processing
wwwnjctlorg
3
Vocabulary
glycolysis
aerobic anabolic pathwayanaerobic
Calvin Cycle
chlorophyllcellular respiration
FADH2
fermentation
lactic acid fermentation
metabolism
ATP
NADHcitric acid cycle
electron transport chain
Krebs cycle
electron acceptor
facultative anaerobe
Acetyl CoshyA
ATP synthase
NADPH
catabolic pathway
ethanol fermentation
cyclic energy transport
light dependent reactionslight independent reactions
Click on each word below to go to the definition
4
Vocabulary
pyruvate
oxidation
reductionpyruvate decarboxylation
phosphorylationoxidative phosphorylation
obligate anaerobeobligate aerobe
photosynthesisphotosystem Iphotosystem II
noncyclic energy transport
thylakoid
Click on each word below to go to the definition
5
Energy Processing Unit Topics
middot Metabolism amp ATP
middot Cellular Respiration
Click on the topic to go to that section
middot Fermentation
middot Photosynthesis
6
Chapter 8Metabolism amp ATP
Return toTable ofContents
7
Metabolism is the totality of an organismrsquos chemical reactions
Metabolism is a property of all life
Metabolic Pathways
8
A metabolic pathway begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
Without enzymes metabolic pathways would proceed very slowly
Metabolic Pathways
enzyme 1 enzyme 2 enzyme 3
A B C D
Starting Molecule
Product
Reaction 1 Reaction 3Reaction 2
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
3
Vocabulary
glycolysis
aerobic anabolic pathwayanaerobic
Calvin Cycle
chlorophyllcellular respiration
FADH2
fermentation
lactic acid fermentation
metabolism
ATP
NADHcitric acid cycle
electron transport chain
Krebs cycle
electron acceptor
facultative anaerobe
Acetyl CoshyA
ATP synthase
NADPH
catabolic pathway
ethanol fermentation
cyclic energy transport
light dependent reactionslight independent reactions
Click on each word below to go to the definition
4
Vocabulary
pyruvate
oxidation
reductionpyruvate decarboxylation
phosphorylationoxidative phosphorylation
obligate anaerobeobligate aerobe
photosynthesisphotosystem Iphotosystem II
noncyclic energy transport
thylakoid
Click on each word below to go to the definition
5
Energy Processing Unit Topics
middot Metabolism amp ATP
middot Cellular Respiration
Click on the topic to go to that section
middot Fermentation
middot Photosynthesis
6
Chapter 8Metabolism amp ATP
Return toTable ofContents
7
Metabolism is the totality of an organismrsquos chemical reactions
Metabolism is a property of all life
Metabolic Pathways
8
A metabolic pathway begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
Without enzymes metabolic pathways would proceed very slowly
Metabolic Pathways
enzyme 1 enzyme 2 enzyme 3
A B C D
Starting Molecule
Product
Reaction 1 Reaction 3Reaction 2
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
4
Vocabulary
pyruvate
oxidation
reductionpyruvate decarboxylation
phosphorylationoxidative phosphorylation
obligate anaerobeobligate aerobe
photosynthesisphotosystem Iphotosystem II
noncyclic energy transport
thylakoid
Click on each word below to go to the definition
5
Energy Processing Unit Topics
middot Metabolism amp ATP
middot Cellular Respiration
Click on the topic to go to that section
middot Fermentation
middot Photosynthesis
6
Chapter 8Metabolism amp ATP
Return toTable ofContents
7
Metabolism is the totality of an organismrsquos chemical reactions
Metabolism is a property of all life
Metabolic Pathways
8
A metabolic pathway begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
Without enzymes metabolic pathways would proceed very slowly
Metabolic Pathways
enzyme 1 enzyme 2 enzyme 3
A B C D
Starting Molecule
Product
Reaction 1 Reaction 3Reaction 2
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
5
Energy Processing Unit Topics
middot Metabolism amp ATP
middot Cellular Respiration
Click on the topic to go to that section
middot Fermentation
middot Photosynthesis
6
Chapter 8Metabolism amp ATP
Return toTable ofContents
7
Metabolism is the totality of an organismrsquos chemical reactions
Metabolism is a property of all life
Metabolic Pathways
8
A metabolic pathway begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
Without enzymes metabolic pathways would proceed very slowly
Metabolic Pathways
enzyme 1 enzyme 2 enzyme 3
A B C D
Starting Molecule
Product
Reaction 1 Reaction 3Reaction 2
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
6
Chapter 8Metabolism amp ATP
Return toTable ofContents
7
Metabolism is the totality of an organismrsquos chemical reactions
Metabolism is a property of all life
Metabolic Pathways
8
A metabolic pathway begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
Without enzymes metabolic pathways would proceed very slowly
Metabolic Pathways
enzyme 1 enzyme 2 enzyme 3
A B C D
Starting Molecule
Product
Reaction 1 Reaction 3Reaction 2
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
7
Metabolism is the totality of an organismrsquos chemical reactions
Metabolism is a property of all life
Metabolic Pathways
8
A metabolic pathway begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
Without enzymes metabolic pathways would proceed very slowly
Metabolic Pathways
enzyme 1 enzyme 2 enzyme 3
A B C D
Starting Molecule
Product
Reaction 1 Reaction 3Reaction 2
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
8
A metabolic pathway begins with a specific molecule and ends with a product
Each step is catalyzed by a specific enzyme
Without enzymes metabolic pathways would proceed very slowly
Metabolic Pathways
enzyme 1 enzyme 2 enzyme 3
A B C D
Starting Molecule
Product
Reaction 1 Reaction 3Reaction 2
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
9
There are two types of metabolic pathways
Catabolic pathways
Anabolic pathways
Metabolic Pathways
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
10
Catabolic pathways break down molecules from the environment
Living things use the energy derived from breaking the bonds in these molecules to build structures and drive cell processes
Catabolic Pathways
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
11
Reactants
Energy
Products
Progress of the reaction
Free energy
Amount of free energy released (ΔGlt0)
Exergonic ReactionCatabolic pathways are exergonic reactions the change in Gibbs free energy is negative Thus they release energy and occur spontaneously
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
12
Anabolic pathways synthesize complex organic molecules and power cell processes using the energy derived from catabolic pathways
Anabolic Pathways
Examplesbuilding bonesbuilding musclebuilding starchpowering active transport
Click here for a pneumonic device
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
13
Reactants
Energy
Products
Progress of the reaction
Amount offree energyrequired(ΔG gt 0)
Free energy
Endergonic ReactionAnabolic pathways are endergonic reactions the change in Gibbs free energy is positive Thus they require an input of energy and do not occur spontaneously
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
14
A process will occur spontaneously if the result is a reduction of the Gibbs Free Energy (G) of the system
G takes into account the resulting change in the energy of a system and the change in its entropy
If the effect of a reaction is to reduce G the process will proceed spontaneously
If ∆G is negative the reaction will occur spontaneously
If ∆G is zero or positive it will not occur spontaneously
Spontaneous Processes
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
15
Free Energy and Metabolism
Biological systems often need an endergonic reaction to occur but on its own it wont proceed spontaneously
To be able to occur the endergonic reaction is coupled to a reaction that is exergonic so that together they are exergonic
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
16
NH2
Glu
Nonshyspontaneous reaction ∆G is positive
∆G = +34 kcalmolNH3Glu
Glutamicacid
Ammonia
+
ATP + H2O ADP
Spontaneous Reaction ∆G is negative
+ Pi
∆G = shy73 kcalmol
∆G = ndash39 kcalmoltogether reactions are spontaneous
Adding Coupled Reactions
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
17
1 A spontaneous reaction _____
A occurs only when an enzyme or other catalyst is present
B cannot occur outside of a living cellC releases free energy when proceeding in the forward
directionD is common in anabolic pathways
E leads to a decrease in the entropy of the universe
Answ
er
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
18
2 Anabolic pathways are ___________ and catabolic pathways are ______________
A spontaneous nonshyspontaneousB endergonic exergonicC exergonic endergonicD endothermic endergonic
Answ
er
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
19
3 Which of the following correctly states the relationship between anabolic and catabolic pathways
A Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways
C Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways
Answ
er
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
20
A cell does three main kinds of work
bull Mechanical (motion)bull Transport (crossing a barrier)bull Chemical (changing a molecule)
To do work cells manage energy resources by energy coupling using an exergonic reaction to drive an endergonic one
Cell Energy
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
21
ATP
Cells can store the energy from catabolic pathways in a molecule called ATP (adenosine triphosphate) ATP can be broken down later to fuel anabolic reactions
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
22
ATP (adenosine triphosphate) includes three phosphate groups (PO4shy3)
Each Phosphate group has an ionic charge of shy3e
In this model of ATP each PO4shy3 is circled in blue
ATP
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
23
ATP
The phosphate groups repel each other since they each have a negative charge
Therefore it requires Work to add the second phosphate group to go from AMP (monophosphate) to ADP (diphosphate)
To add the third group to go from ADP to ATP (triphosphate) requires even more work since it is repelled by both of the other phosphate groups
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
24
ATPThis is like the work in compressing a spring
The energy from the work needed to bring each phosphate group to the molecule is stored in that phosphate bond
When the bond is broken to go from ATP to ADP significant energy is released
Going from ADP to AMP releases less energy since there is less total charge in ADP than ATP
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
25
The bonds between the phosphate groups of ATPrsquos tail can be broken by hydrolysis
Energy is released from ATP when the terminal phosphate bond is broken
The released energy is equal to the work that was done to form the bond That work overcame the electrostatic repulsion between the last phosphate group and the initial ADP molecule
The result is a chemical change to a state of lower free energy
ATP
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
26
In the living systems the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction
Overall the coupled reactions are exergonic
ATP
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
27
ATP Performs Work
ATP drives endergonic reactions by phosphorylation transferring a phosphate group to some other molecule such as a reactant
The recipient molecule is now phosphorylated
The three types of cellular work are powered by the hydrolysis of ATP
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
28
NH2
Glu
Pi
P i
P i Pi
Glu NH3
P
P
P
ATPADP
Motor protein
Mechanical work ATP phosphorylates motor proteins
Protein moved
Membraneprotein
Solute
Transport work ATP phosphorylates transport proteins
Solute transported
Chemical work ATP phosphorylates key reactants
Reactants Glutamic acidand ammonia
Product (glutamine)made
+ +
+
ATP Performs Work
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
29
The Regeneration of ATP
ATP is a renewable resource that is regenerated by addition of a phosphate group to ADP
The energy to phosphorylate ADP comes from catabolic reactions in the cell
The chemical potential energy temporarily stored in ATP drives most cellular work
Each cell is converting millions of ATP to ADP and back again every second
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
30
Pi
Energy for cellular work (endergonic energy consuming processes)
Energy from catabolism(exergonic energyyielding processes)
+
ATP
ADP
The Regeneration of ATP
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
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Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
31
4 In general the hydrolysis of ATP drives cellular work by _____
A releasing free energy that can be coupled to other reactionsB releasing heatC acting as a catalystD lowering the free energy of the reaction An
swer
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
32
5 What best characterizes the role of ATP in cellular metabolism
A The release of free energy during the hydrolysis of ATP heats the surrounding environment
BThe free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate
C It is catabolized to carbon dioxide and waterD The ΔG associated with its hydrolysis is positive An
swer
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
33
6 Which of the following is not an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATPA Mechanical work such as the movement of the cell
B Transport work such as the active transport of an ion into a cell
C Chemical work such as the synthesis of new proteins
D The production of heat which raises the temperature of the cell
Answ
er
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
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The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
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CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
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92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
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Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
34
Cellular Respiration
Return toTable ofContents
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
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20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
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The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
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The Versatility of Catabolism
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Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
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However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
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Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
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CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
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Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
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The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
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23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
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Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
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Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
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Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
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26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
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What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
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This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
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eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
35
Equilibrium and Metabolism
Reactions in a closed system eventually reach equilibrium and then stop
Life is not in equilibrium
Life is an open system experiencing a constant flow of materials and energy
Life cannot survive without connection to the environment
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
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The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
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Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
36
The Production of ATPCatabolic Pathways
Cellular respiration is a catabolic pathway that consumes organic molecules and yields ATP
Carbohydrates fats and proteins can all fuel cellular respiration
Well look first at the simplest case the breakdown of the sugar shy glucose
But before doing that we have to learn about two molecules that are essential to respiration
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
37
NAD+ + 2H+ + 2eshy + Energy NADH + H+
NAD+ and FADThe molecules NAD+ and FAD are used to store and later release energy during respiration they are key to respiration
Each molecule has two forms each form stores a different amount of energy So moving between those two forms either stores chemical potential energy or releases it
Here are the reactions
FAD + 2H+ + 2eshy + Energy FADH2
The double arrows indicate that each reaction is reversible they can proceed in either direction When the reaction goes to the right energy is stored When it goes to the left energy is released
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
38
NAD+ and FAD
The amount of energy that is useable when the reaction goes to the left depends on the availability of electron acceptors Without a molecule such as O2 to accept the excess electrons the energy stored in NADH and FADH2 cannot be used to make ATP
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
39
Electron AcceptorsOxygen is the best electron acceptor because it generates the greatest free energy change (∆G) and produces the most energy
In the absence of oxygen other molecules such as nitrate sulfate and carbon dioxide can be used as electron acceptors
If O2 is present bull 1 NADH stores enough energy to create about 3 ATPs
bull 1 FADH2 stores enough energy to make about 2 ATPs
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
40
7 NADH is converted to NAD+ During this process
A energy is releasedB energy is storedC no energy is stored or released
Answ
er
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
41
8 FADH2 is converted to FAD During this process
A energy is storedB energy is releasedC no energy is stored or released
Answ
er
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
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Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
42
Reduction and Oxidation
When we go from left to right we are adding electrons to a molecule That is called reducing the molecule or the process of reduction
Going from right to left we are taking electrons from a molecule That is called oxidizing the molecule or the process of oxidation
NAD+ + 2H+ + 2eshy + Energy NADH + H+
FAD + 2H+ + 2eshy + Energy FADH2
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
43
The reason for the term oxidation is that this is the effect that oxygen usually has it takes electrons from a molecule oxidizing the molecule
The rusting of iron is an example of oxidation oxygen is taking electrons from the metal oxidizing it
Oxidation
4 Fe + 3 O2 rarr 2 Fe2O3
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
44
Reduction and Oxidation
LEO says GER
LosingElectrons isOxidation
GainingElectrons is Reduction
Since it doesnt seem right that adding electrons is called reduction heres a way to remember these two terms
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
45
9 Which of the following cannot act as an electron acceptor
A sulfateB oxygenC ammoniaD nitrate
Answ
er
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
46
10 The loss of an electron is __________ and the gain of an electron is ____________
A oxidation reductionB reduction oxidationC catalysis phosphorylationD phosphoroylation catalysis
Answ
er
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
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Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
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13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
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14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
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Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
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15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
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16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
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17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
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So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
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Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
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18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
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Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
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Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
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We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
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20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
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21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
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22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
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The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
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The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
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However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
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Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
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CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
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Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
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The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
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23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
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24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
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25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
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Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
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Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
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Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
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26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
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27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
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28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
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29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
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What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
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This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
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30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
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31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
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32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
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eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
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33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
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34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
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Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
47
11 NADH is the reduced form of NAD+
True
False
Answ
er
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
48
Types of Cellular Respiration
Cells follow different paths of cellular respiration depending on the presence or absence of oxygen
Cells can be classified into 3 categories based on their response to oxygen
bull Obligate Anaerobes shy which cannot survive in the presence of oxygen
bull Obligate Aerobes shy which require oxygen
bull Facultative Anaerobes shy which can survive in the presence or absence of oxygen
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
49
The Stages of Respiration
Cellular respiration consists of four stages
bull Glycolysis bull Pyruvate Decarboxylationbull The Citric Acid Cycle (Krebs Cycle)bull Oxidative Phosphorylation
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
50
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Glycolysis means the splitting of glucose
Some ATP is needed to start the process (Ea)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
Glycolysis
Glycolysis is the first stage of cellular respiration It involves the breakdown of glucose a 6 carbon sugar into 2 molecules of pyruvate a 3 carbon sugar
Glycolysis means the splitting of glucose
The net result isa net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates
Some ATP is needed to start the process (Ea)
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
51
12 Until 25 billon years ago there was no oxygen in the Earths atmosphere Which of the following was also not present
A facultative anaerobesB obligate anaerobesC obligate aerobesD bacteria
Answ
er
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
52
13 How much activation energy is required to start glycolysis
A 0 ATPB 1 ATPC 2 ATPD 4 ATP
Answ
er
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
53
14 The net products of glycolysis are
A 2 pyruvateB 2 NADH and 2 pyruvateC 2 ATP 2 NADH and 2 pyruvateD 4 ATP 2 NADH and 2 pyruvate
Answ
er
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
54
Pyruvate Decarboxylation (PD)The Citric Acid Cycle can only process 2shycarbon molecules and pyruvate is a 3shycarbon molecule C3H4O3
PDC
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
2 CO2
2 Acetyl CoshyA
PD is an enzyme catalyzed reaction that takes the 2 pyruvate molecules and converts them to 2 Acetyl CoshyA molecules these are 2shycarbon molecules
Energy is stored during PD by the converting 2 NAD+ to 2 NADH and the extra pyruvate carbons are expelled as CO2
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
55
The Citric Acid Cycle
This shows one cycle which is due to one Acetyl CoshyA molecule
To account for one glucose molecule two cycles are needed
Lets tally up the output for one cycle to confirm our results
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
56
1 ATP3 NADH1 FADH2
The Citric Acid Cycle
1 ATP3 NADH1 FADH2
2 ATP6 NADH2 FADH2
But 1 glucose molecule yields 2 Acetyl CoshyA molecules (therefore 2 turns of the cycle) yielding
This is one turn of the cycle due to 1 Acetyl CoshyA Note the production of
Click here for a video of the Citric Acid Cycle
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
57
The citric acid cycle is sometimes called the Krebs cycle
The cycle breaks down one AcetylshyCoA for each turn generating1 ATP 3 NADH 2 CO2 and 1 FADH2 per AcetylshyCoA
Since 2 AcetylshyCoA molecules were created from each glucose the
Citric Acid Cycle creates 2 ATP 6 NADH 4CO2 and 2 FADH2 for each glucose molecule
The Citric Acid Cycle
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
58
15 Glycolysis produces ____ ATP
Pyruvate Decarboxylation produces ____ ATP
The Citric Acid Cycle produces _____ ATP
A 1 1 2B 4 0 2C 4 0 4D 2 0 2
Answ
er
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
59
16 During pyruvate decarboxylation 3shycarbon pyruvate is converted to 2shycarbon AcetylshyCoA What happens to the excess carbons atoms in this process
A They are expelled in molecules of CH4
B They are expelled in molecules of CO2
C They are covalently bonded to NADHD They are recycled to reform glucose
Answ
er
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
60
17 In total the first 3 stages of cellular respiration produce how many molecules of carbon dioxide
A 1B 2C 3D 6
Answ
er
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
61
So far weve done a lot of work to just get a net gain of 4 ATPs
But we have stored a lot of potential energy in the form of
NADH and FADH2
The big energy payoff is in oxidative phosphorylation where we convert the energy stored in those molecules to ATP
Oxidative Phosphorylation (OP)
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
62
Stage NADH FADH2 ATP
Glycolysis 2 0 2
PD 2 0 0
CAC 6 2 2
Total 10 2 4
Oxidative Phosphorylation (OP)Were now going to convert all the NADH and FADH2 into ATP so the energy can be stored throughout the cell
Heres what we start this cycle with
When O2 is present we get about 3 ATPs per NADH and 2 ATPs per FADH2 So how many ATPs would we have at the end of this next stage
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
63
Oxidative phosphorylation is powered by the electron transport chain One way to think of the ETC is as a proton pumpThe ETC transports electrons through chemical reactions out and then back through a plasma membrane The net effect is to pump protons from the inside to the outside of a plasma membrane creating a proton gradient which is used to power oxidative phosphorylation
Electron Transport Chain (ETC)
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
64
Electron Transport Chain (ETC)
The electron path is shown in black
The proton path in red
The ETC generates no ATP but enables Oxidative Phosphorylation which accounts for most of the ATP produced
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
65
Anaerobic ETC
For the first 2 billion years of life on Earth anaerobic (no O2) respiration was the only means of obtaining energy from food
These organisms used the electron acceptors NO3shy SO42shy or
CO2 to pull the electrons through the ETC These molecules would accept the electrons at the end of the chain forming N2 H2S and CH4 respectively
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
66
Aerobic ETC
Click here for a video of the ETC
But then the Oxygen Revolution occurred about 25 BYA flooding the planet with oxygen
In aerobic respiration the final electron acceptor of the electron transport chain is O2 forming water (H2O) Oxygen strongly attracts electrons in order to fill its outer shell This stronger pull makes much more energy available to life enabling the more complex food chains we see today
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
67
18 Which of the following is created during the electron transport chain in human cells
I ATP
II NADH
III proton gradient
IV H2O
A I II III IVB I II onlyC III onlyD III IV only An
swer
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
68
19 Obligate aerobes use which of the following as their final electron acceptor
A CO2
B NO3shy
C O2D SO42shy
Answ
er
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
69
Oxidative Phosphorylation (OP)The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside The excess protons outside are strongly attracted to the inside but are blocked by the membrane One path is open to the protons but they must do work to use it
ATP Synthase is essentially a motor constructed of proteins The protons must travel through that motor in order to return to the cell creating an electric current that powers the motor
As the motor turns it adds a phosphate group to ADP creating ATP Electrical energy is transformed to chemical energy
Click here for a video of ATP Synthase
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
70
Oxidative PhosphorylationThe Hydroelectric Analogy
The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
71
Like oxidative phosphorylationit creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline transforming it to kinetic energy
Oxidative PhosphorylationThe Hydroelectric Analogy
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
72
Massive turbines are spun causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy
Oxidative PhosphorylationThe Hydroelectric Analogy
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
73
We calculated earlier that we would expect to get 38 ATP molecules by the time wed converted all the NADH and FADH2 to ATP
The actual yield is between 36 shy 38 ATP molecules per glucose molecule
The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC
Aerobic Respiration
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
74
20 ATP synthase
A synthesizes ATPB is an enzymeC is a protein complexD all of the above
Answ
er
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
75
21 Energy released by the electron transport chain is used to pump H+ ions into which location
A Outside the membraneB Inside the membrane
Answ
er
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
76
22 What is the maximum number of ATP produced from a breakdown of a glucose molecule
A 4B 18C 36D 38
Answ
er
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
77
The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration
middot Glycolysis accepts a wide range of carbohydrates
middot Proteins must be digested to amino acids amino groups can feed glycolysis or the citric acid cycle
middot Fats are digested to glycerol which is used in glycolysis An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
78
The Versatility of Catabolism
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
79
Fermentation
Return toTable ofContents
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
80
When no electron acceptors are available obligate anaerobes and facultative anaerobes can still break down glucose to release energy through a process called fermentation
Fermentation
Fermentation begins just as cellular respiration does with glycolysis
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
81
FermentationGlycolysis results in 2 pyruvate molecules and 2 NADH2
molecules Without an electron acceptor the energy stored in these molecules cant be used
The net energy gain is just 2 ATPs (Remember 2 were invested and 4 were produced netting 2)
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
82
However the Pyruvate still needs to be cleared from the cell and the NADH converted back to NAD+ to begin another cycle
The process of doing this is called fermentation
No additional energy is released during this process
Fermentation
C6H12O6(Glucose)
Gycolysis
2 ATP
4 ATP2 NADH
2 C3H4O3 (Pyruvate)
2 NAD+
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
83
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
Types of FermentationThere are two types of fermentation
bull Lactic acid fermentation
bull Ethanol fermentation
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
84
CO2 amp Ethanol
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
Fermentation
2 NADH
2 NAD+
2 C3H4O3 (Pyruvate)
CO2 amp 2 Ethanol
2 LacticAcid
Lactic AcidFermentation
EthanolFermentation
OR
1 glucose molecule had yielded 2 ATPs 2 Pyruvates and 2 NADHs That is the input to the fermentation stage of anaerobic respiration
FermentationFermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule
The pyruvates and NADHs are fermented into 2 NAD+ and either Lactic Acid or CO2 amp Ethanol
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
85
Fermentation
The result of the combined steps of glycolysis and fermentation is
bull The input is 1 Glucose + 2 ATP molecules
bull The output is 4 ATP molecules (for a net gain of 2 ATPs)
In addition
bull Lactic Acid fermentation results in lactic acid
bull Ethanol fermentation results in ethanol and CO2
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
86
The big difference is that for each glucose molecule
aerobic cellular respiration yields 36 to 38 ATPs
fermentation yields only 2 ATPs
Cellular Respiration vs Fermentation
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
87
bull Some anaerobic bacteria rely soley on fermentation such as lactobacillus which is used to make cheese and yogurt
bull The alcohol in wine beer etc results from yeast (a facultative anaerobe) undergoing ethanol fermentation
bull Bread rises due to the release of CO2 bubbles by fermenting yeast
bull Your muscles burn after a strenuous workout because they cant get enough O2 so they perform lactic acid fermentation Lactic acid results in soreness
Examples of Fermentation
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
88
23 When a cell has completed glycolysis and lactic acid fermentation the final products are
I Lactic acid
II Ethanol
III Carbon dioxide
IV NADH
V ATP
A I II III IV VB I II III VC I IV VD I V
Answ
er
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
89
24 Bread rises due to the production of _______ during fermentation
A ethanolB carbon dioxideC lactic acidD pyruvate
Answ
er
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
90
25 Muscles produce lactic acid during strenuous exercise Therefore muscles are an example of what kind of cell
A facultative anaerobeB facultative aerobeC obligate anaerobeD obligate aerobe
Answ
er
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
91
Photosynthesis
Return toTable ofContents
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
92
Respiration gets energy from glucose and stores it as ATP
But what is the source of glucose
And where did the oxygen that flooded Earth 25 BYA come from
Photosynthesis
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
93
Heres the balanced chemical equation for aerobic respiration
And heres the balanced chemical equation for photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Aerobic Respiration vs Photosynthesis
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
94
Aerobic respiration uses oxygen (O2) and glucose (C6H12O6) to create carbon dioxide (CO2) and water (H2O)and release energy
Photosynthesis is the exact opposite it takes carbon dioxide (CO2) and water (H2O) plus energy to make glucose (C6H12O6) and oxygen (O2)
Aerobic Respiration vs Photosynthesis
C6H12O6 + 6O2 6CO2 + 6H2O + ATP
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
95
Photosynthesis and Respiration
Summing these two equations reveals that the ATP used by cells is derived from light energy from the sun That is the source of energy for most life on Earth
C6H12O6 + 6O2 6CO2 + 6H2O + ATP (Energy)
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
Light Energy ATP (Energy)
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
96
Except for a small number of bacteria that live on chemical reactions in challenging environments the energy for all life on Earth comes from these processesfrom the energy of sunlight Even though not every organism undergoes photosythesis the products that plants produce are used in reactions that consumers use In this way you can say that
You are solar powered
Light Energy ATP (Energy)
Photosynthesis and Respiration
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
97
26What are the reactants of cellular respiration
A Oxygen and Water
B Glucose and Carbon Dioxide
C Glucose and Water
D Glucose and Oxygen Answ
er
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
98
27What are the products of photosynthesis
A Glucose and Oxygen
B Oxygen and Water
C Glucose and Carbon Dioxide
D Carbon Dioxide and Water Answ
er
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
99
28What are the reactants of photosynthesis
A Carbon Dioxide and Water
B Oxygen and Water
C Glucose and Oxygen
D Glucose and Carbon Dioxide Answ
er
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
100
29Photosynthesis ____________ energy whereas cellular respiration __________ energy
A consumes produces
B produces consumes
C produces produces
D consumes consumes Answ
er
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
101
What is the source of glucose
Where did the oxygen that flooded Earth 25 BYA come from
Our Original Questions
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
102
The products of photosynthesis are
bull oxygen (O2) bull glucose (C6H12O6)
Photosynthesis produces the glucose that feeds respiration and eventually all of us
Photosynthesis also produces the oxygen that filled the atmosphere and made complex life as we know it possible
Photosynthesis
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
103
Photosynthesis and the addition of oxygen to Earths atmosphere began about 25 BYA and was having a major impact by 20 BYA
This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of obligate anaerobes Some survive today but only in locations where they are not exposed to the atmosphere
The Oxygen Catastrophe
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
104
This simple equation sums up the result of photosynthesis its reactants and products
However the processes that make photosynthesis possible are not very simple
Just like the four stages of respiration result in a simple equation the process itself is complicated
Similarly the process of photosynthesis is complicated And in some ways similar to the steps of respiration but backwards
Photosynthesis
6CO2 + 6H2O + Light Energy C6H12O6 + 6O2
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
105
30 In the comparison of aerobic respiration to photosynthesis which statement is true
Aoxygen is a waste product in photosynthesis but not in respiration
Bglucose is produced in respiration but not in photosynthesis
Ccarbon dioxide is formed in photosynthesis but not in respiration
D water is formed in photosynthesis but not in respiration
Answ
er
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
106
During respiration the molecules NAD+and FAD are used to store energy
Photosynthesis uses the molecule NADP+ which is a lot like NAD+ to store energy and convert it between its two stages
The reduced form of NADP+ is NADPH
NADPH
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
107
Photosynthesis also depends on chlorophyll a molecule that absorbs red and violetshyblue light and uses it to energize electrons to a higher energy level
Chlorophyll
Chlorophyll gives plants their green color
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
108
Chlorophyll is housed in thylakoids membraneshybound structures within photosynthetic cells
Thylakoids
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
109
31 NAD+ is to NADP+ as NADH is to ______
A NADP2+
B NADPC NADPHD NADPH2
Answ
er
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
110
32 Which of the following is found stored in the thylakoid
A ATPB chlorophyllC NADHD NADPH
Answ
er
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
111
There are two types of photosynthesis
Cyclic Energy Transport
NonshyCyclic Energy Transport
Two Types of Photosynthesis
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
112
Cyclic Energy Transport was probably the first type of photosynthesis to originate
It does not create glucose it just converts solar energy to ATP
Cyclic Energy Transport
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
113
eshy
eshy
Photosystem IElectron
Transport Chain
ADP + P i
ATPATP
Synthase
Energy of m
olecules
chlorophyll
eshy
eshy
photon
This process is cyclic because the final electrons return to chlorophyll after ATP is generated
Cyclic Energy TransportCyclic Energy Transport uses Photosystem I a protein complex embedded in the thylakoid membrane to convert light energy to ATP
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
114
33 Noncyclic energy transport arose before cyclic energy transport
True
False
Answ
er
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
115
34 Which of the following statements about cyclic energy transport is true
A Cyclic energy transport requires waterB Glucose is produced by cyclic energy transportC Cyclic energy transport reduces NADP+
D Light energy is converted to chemical energy during cyclic energy transport
Answ
er
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
116
There are two major stages to Noncyclic Energy Transport
Light Dependent Reactions
Light Independent Reactions (Calvin Cycle)
Noncyclic Energy Transport
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
117
Light Dependent Reactions occur in membrane bound structures called thylakoids
Its necessary to have a membrane surface separating the inside from the outside on an enclosed volume thylakoids provide that The inside is called the lumen the outside is called the stroma
Light Dependent Reactions
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
118
Light Dependent Reactions
2 H2O + 2 NADP+ + 3 ADP + 3 Pi O2 + 2NADPH + 3 ATP
The Light Dependent Reactions use light energy and water to form ATP NADPH and oxygen gas
This process requires 2 photosystems Photosystem II and Photosystem I They occur in this order (they were named in the order in which they were discovered)
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
119
ThylakoidThis shows the membrane separating the stroma from the lumen the two photosystems and the enzymes ATP Synthase and NADP Reductase
The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma and a deficit in the lumen
The only way protons can get back to the lumen is through ATP Synthase to produce ATP
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
120
Photosystem IIFirst Photosystem II absorbs light and energizes electrons splitting a water molecule in the process Those are used to pump protons across the membrane creating an electrical potential difference which is used to create ATP
eshy
eshy
Photosystem IIElectron
Transport Chain
ADP + P i
ATPATP
Synthase
chlorophyll
eshy
eshy
photon
to Photosystem IH2O
O2+2H+
Energy of m
olecules
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
121
Photosystem I
chlorophyll
eshy
eshyeshy
Photosystem I
eshy
from Photo
system II
NADP Reductase NADP+
NADPH
photon
Energy of m
olecules
Then Photosystem I absorbs more light and reshyenergizes those electrons They are used to store energy by using NADP Reductase to reduce NADP+ to NADPH (adding electrons to NADP+ instead of returning them to chlorophyll as in cyclic energy transport)
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
122
35 The inside of the thylakoid is called the ______ and the outside is called the ______
A lumen stromaB stroma lumen
Answ
er
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
123
36 Light dependent reaction produce ____ ATP and ____ NADPH for each O2 producedA 1 1B 2 3C 3 2D 2 4
Answ
er
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
124
37 Water is split releasing O2 in which protein complex
A photosystem IB photosystem IIC ATP synthaseD NADP reductase
Answ
er
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
125
Light Independent ReactionsThe ATP and NADPH created during the light dependent reactions proceed to the Light Independent Reaction The light independent reactions are also know as the Calvin Cycle or Dark Reactions
These reactions can occur in light or dark thus dark reactions is not an accurate name
The Calvin Cycle uses the ATP and NADPH to convert CO2 into Glucose (C6H12O6) in a multi step process
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
126
Light Independent Reactions
In 3 turns of the cycle we use9 ATPand 6 NADPHand 3 CO2
to make a 3shycarbon sugar
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
127
Light Independent Reactions
To make one 6shycarbon glucose molecule18 ATPand 12 NADPHand 6 CO2 are required
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
128
The Carbon Cycle
The Calvin Cycle is also called Carbon Fixing
This means that carbon a gas in the atmosphere in the form of CO2 is turned into a solid as a glucose When glucose is used in respiration that carbon is then released back into the atmosphere
This process of fixing and releasing carbon is called the Carbon Cycle Carbon is not being created or destroyed but cycles through the environment
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
129
The Light Reactions produce equal amounts of ATP and NADPH but the Calvin Cycle use more ATP (18) than NADPH (12) to make a glucose molecule
To have enough ATP photosynthetic organisms use Cyclic Energy Transport to create the needed ATP
Cyclic vs Noncyclic Energy Transport
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
130
38 Carbon dioxide is fixed in the form of glucose in
A Krebs cycleB lightshydependent reactionsC Calvin cycleD cyclic energy transport
Answ
er
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
131
39 During what stage of photosynthesis are ATP and NADPH coverted to ADP + Pi and NADP+
A light dependent reactionsB light independent reactionsC photosystem ID photosystem II
Answ
er
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
132
40 Which of the following statements about photosynthesis is true
AThe light dependent reactions can only occur in the light the light independent reactions can only occur in the dark
B Cyclic energy transport is more efficient at producing glucose than noncyclic energy transport
C The light dependent reactions produce ATP which is used to power the Calvin cycle
D Cyclic energy transport occurs only in bacteria
Answ
er
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
133
41 The Calvin cycle is an anabolic pathway
True
False
Answ
er
True
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
134
Global Climate Change
The carbon cycle plays a key role in Global Climate Change
Photosynthesis releases oxygen into the air but also takes CO2 out of the air
CO2 is a greenhouse gas it absorbs infrared light that would otherwise carry heat away from Earth into space cooling Earth
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
135
Global Climate Change
If it were not for CO2 and other greenhouse gases Earth would be far colder perhaps too cold to support life as we know it
Greenhouse gases are essential for life
However the amount of greenhouse gases in Earths atmosphere is critical to maintaining a constant average temperature for the planet
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
136
Global Climate ChangeA great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of years effectively taking that carbon out of the carbon cycle
That reduced the CO2 in the atmosphere reducing the temperature of Earth by allowing more heat to leave leading to our current temperature
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
137
Global Climate Change
The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that longshydead plant and animal life
As we burn those fuels we are releasing CO2 back into the atmosphere increasing the greenhouse gases in the atmosphere
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
138
Global Climate Change
As a result more heat is being trapped in our atmosphere the balance of energy brought to Earth by solar energy and released from Earth in infrared radiation is being changed
This is causing Earths average temperature to rise
The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily
But it is projected that there will be massive changes in climate in the future with accompanying changes in sea level crops plant and animal life etc
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
139
42 Greenhouses gases are dangerous and should be reduced as much as possible
True
False
Answ
er
False
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
140
43 Carbon was used from the carbon cycle reducing CO2 in the air as __________
A the amount of life on Earth decreasedB as animals died and were buried under earthC fermentation beganD All of the aboveE None of the above
Answ
er
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
141
44 A very warm winter in New Jersey this year would indicate that global climate change is occurring
True
False
Answ
er
False
142
Attachments
08_15HowEnzymesWork_Aswf
142
Attachments
08_15HowEnzymesWork_Aswf
Attachments
08_15HowEnzymesWork_Aswf
