Chapter 15 Cellular Respiration 6
Transcript of Chapter 15 Cellular Respiration 6
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15.1: Types of respiration: aerobic and
anaerobic
15.2 : Aerobic respiration
15.3 : Anaerobic respiration :
fermentation and application
Electrons
carried
via NADH
Electrons carried
via NADH and
FADH2
Citric
acid
cycle
Pyruvate
oxidation
Acetyl CoA
Glycolysis
Glucose Pyruvate
Oxidative
phosphorylation:
electron transport
and
chemiosmosis
CYTOSOL MITOCHONDRION
ATP ATP ATP
Substrate-level
phosphorylation
Substrate-level
phosphorylation
Oxidative
phosphorylation
A membrane-bound enzyme in chloroplast and
mitochondria that uses the energy of protons
flowing through it to synthesize ATP.
What is ATP Synthase?
a) Explain complete oxidation of one molecule of
glucose in active cells.
b) Explain what is meant by fermentation.
c) State the importance of fermentation in industry
i) Bakery
ii) Wine, beverage and alcohol production
Iii) Dairy industry cheese and yoghurt
iv) Local examples could be introduced
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An Accounting of ATP Production
by Cellular Respiration
During cellular respiration, most energy flows
in this sequence:
GlucoseNADHelectron transport
chain proton-motive force ATP
About 34% of the energy in a glucose molecule
is transferred to ATP during cellular respiration
Making about 32 ATP.
2011 Pearson Education, Inc.
Cellular Respiration Produces
ATP
MITOCHONDRION2 NADH
2 NADH 2 NADH 6 NADH
2 FADH2
2 FADH2
or
2 ATP2 ATP about 26 or 28 ATP
Glycolysis
Glucose 2 Pyruvate
Pyruvate oxidation
2 Acetyl CoACitricacidcycle
Oxidativephosphorylation:electron transport
andchemiosmosis
CYTOSOL
Maximum per glucose:About
30 or 32 ATP
ATP Production
by Cellular RespirationMalate shuttle
Glycerol shuttle
Glucose
PyruvatePyruvate
2 ATP/glycolysis
(Substrate Level)
2 NADH
Acetyl - CoA
1 NADH
1 ATP/cycle
(Substrate level)
3 NADH
1 FADH2
x 3 ATP/NADH =
x 3 ATP/NADH = 3 ATP
x 3/NADH = 9 ATP/cycle
x 2/FADH = 2 ATP/cycle
Malate shuttle
Oxidation of glucose in
active cells.
Substrate Level Phosphorylation : 3 ATP
Oxidative Phosphorylation : 20 ATP
23 ATP
Glucose
PyruvatePyruvate
2 ATP/glycolysis
(Substrate Level)
2 NADH
Acetyl - CoA
2 NADH
2 ATP
(Substrate level)
6 NADH
2 FADH2
x 3 ATP/NADH =
x 3 ATP/NADH = 6ATP
x 3/NADH = 18 ATP
x 2/FADH = 4 ATP
Malate shuttle
Complete oxidation of glucose
in active cells.
Substrate Level Phosphorylation : 4 ATP
Oxidative Phosphorylation : 34 ATP
38 ATPEnergy Yield per Glucose Molecule
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ATP yield from completeoxidation of glucose
Glycolysis: Glucose into pyruvate 2 ATPGlycolysis: 2 NADH
(Glycerol shuttle = 4 ATP)
(Malate shuttle = 6 ATP) In Active Cells
4 ATPor
6 ATPPyruvate (2) to acetyl CoA yield 2 NADH 6 ATP
Acetyl CoA (2) via Kreb cycle
(2 GTP = 2 ATP)
(6 NADH = 18 ATP)
(2 FADH2 = 4 ATP)
24 ATP
TOTAL 36 or 38 ATP
Where did the glucose come from? Where did the O2 come from?
Where did the CO2 come from?
Where did the H2O come from?
Where did the ATP come from?
What else is produced that is not listed in thisequation?
Why do we breathe?
C6H12O6 6O2 6CO2 6H2O ~36 ATP+ + +
Any Questions??
What is the final electron acceptor in electron
transport chain?
O2
So what happens if O2 unavailable?
ETC backs up
ATP production ceases
cells run out of energy and you die!
Fermentation
and
Anaerobic Respiration
Most cellular respiration requires O2 to produce
ATP.
Without O2, the electron transport chain will cease
to operate.
In that case, glycolysis couples with fermentation
or anaerobic respiration to produce ATP.
Less efficient than aerobic respiration.
Only produce 2 ATP per glucosemolecule.
2011 Pearson Education, Inc.
Glucose
CYTOSOLGlycolysis
Pyruvate
No O2 present:Fermentation
O2
present:
Aerobic cellular
respiration
Ethanol,
lactate, or
other products
Acetyl CoA
MITOCHONDRION
Citric
acid
cycle
A catabolic pathway in which inorganic molecules(Sulfate) other than oxygen accept electrons at the
'down hill' end of electron transport chains.
(Campbell, 9th edition)
other than O2, for example sulfate
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A catabolic process that makes a limited
amount of ATP from glucose (or otherorganic molecules) without an electron
transport chain and that produces a
characteristic end product, such as ethyl
alcohol or lactic acid.
(Campbell, 9th edition)
Lactate/Lactic acid
FermentationAlcoholic
Fermentation
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Animation: Fermentation OverviewRight-click slide / select Play
CO2 is released from
the pyruvate,
converting pyruvate
into acetaldehyde.
acetaldehyde reduced
by NADH to Ethanol.
2 ADP 2 P i 2 ATP
GlucoseGlycolysis
2 Pyruvate
2 CO22 NAD
2 NADH
2 Ethanol2 Acetaldehyde
(a) Alcohol fermentation
2 H
Fermentation by yeast
(a fungus) is used in
brewing, wine making
and bakery.
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Pyruvate is reduced to
NADH, forming lactate
as an end product, with
no release of CO2.
By some fungi and
bacteria is used to make
cheese and yogurt
Human muscle cells use
lactic acid fermentation
to generate ATP when
O2 is scarce.
(b) Lactic acid fermentation
2 Lactate
2 Pyruvate
2 NADH
Glucose Glycolysis
2 ADP 2 P i 2 ATP
2 NAD
2 H
2 ADP 2 ATP
Glucose Glycolysis
2 Pyruvate
2 CO222 NADH
2 Ethanol 2 Acetaldehyde
(a) Alcohol fermentation (b) Lactic acid fermentation
2 Lactate
2 Pyruvate
2 NADH
Glucose Glycolysis
2 ATP2 ADP2 Pi
NAD2 H
2 Pi
2NAD2 H
Wine Bakery
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Aerobic Fermentation
Need the O2 as a last electronaccepter
No need O2
Complete glucose oxidation not complete
Produce energy, CO2,and H2O Produce energy, lactic acid
(animal), ethanol + CO2 in
yeast.
Aerobic Fermentation
More energy per glucose released. Less Energy released
Phosphorylation oxidative occurs,
produce many ATP (38 @36 ATP)
No Phosphorylation oxidative.
Only 2 ATP produce
Involve glycolysis and Krebs cycle Only glycolysis, no Krebs cycle
Reduced products formed :
Water
Reduced products formed:
Reduced organic compounds
(alcohol and lactate)
Aerobic Fermentation
Mechanism of ATP Synthesis:
Substrate level phosphorylation
Oxidative /Chemiosmosis
Mechanism of ATP Synthesis:
Substrate level phosphorylation
Immediate fate of electron
in NADH :
Transferred to electron transport
chain
Immediate fate of electron
in NADH :
Transferred to organic molecules
Terminal electron acceptor of
electron transport chain is oxygen.
No electron transport chain
Photosynthesis