Energy Releasing Pathways (Cellular Respiration) I. Introduction A. History.
Energy Releasing Pathways ATP
description
Transcript of Energy Releasing Pathways ATP
![Page 1: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/1.jpg)
Energy Releasing Pathways
ATP
![Page 2: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/2.jpg)
Aerobic Respiration
•A redox process•Glucose contains energy
that can be converted to ATP
•Uses oxygen therefore aerobic
![Page 3: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/3.jpg)
Cellular Energy Transfer• Cells transfer energy
by redox reactions• Remember:
– oxidation is the loss of electrons
– reductions is the gain of electrons
• Oxidation involves loss of energy
• Reduction involves the gain of energy
![Page 4: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/4.jpg)
![Page 5: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/5.jpg)
Aerobic Respiration- Redox
• C6H12O6 + 6 O2 + 6 H2O 6 CO2 + 12 H2O + Energy
• Water is both a reactant and a product
• Glucose is oxidized to form CO2
• C6H12O6 + 6 O2 + 6 H2O 6 CO2 + 12 H2O + Energy
• Oxygen is reduced, forming water
• C6H12O6 + 6 O2 + 6 H2O 6 CO2 + 12 H2O + Energy
• The electrons produced are used to form ATP
oxidation
reduction
![Page 6: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/6.jpg)
Aerobic Respiration- 4 Stages
•Glycolysis•Formation of acetyl coenzyme
A•Citric Acid Cycle•Electron transport system and
chemiosmosis
![Page 7: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/7.jpg)
Glycolysis
•Glucose is converted to 2 3-carbon molecules of pyruvate
•ATP and NADH are formed•Occurs in the cytosol
•Yellow- products•Green- reactants
![Page 8: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/8.jpg)
Glycolysis Pyruvate Yield• Glycolysis means “sugar splitting”• One 6-carbon molecule is converted to
two 3-carbon molecules• Occurs in cytosol• Occurs in both aerobic and anaerobic
conditions• A series of reactions; each catalyzed by
a different enzyme• Glucose yields two pyruvates
![Page 9: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/9.jpg)
![Page 10: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/10.jpg)
![Page 11: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/11.jpg)
Glycolysis• First phase requires ATP
investment
G3P
2 ATPs used
![Page 12: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/12.jpg)
Glucose
2 glyceraldehyde-3-phosphate (G3P)
Fructose- 1,6-diphosphate
2 ATPs used
PHASE 1
![Page 13: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/13.jpg)
Glycolysis• Second phase yields NADH and
ATP
![Page 14: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/14.jpg)
G3P
Pyruvate
G3P
Pyruvate
+ 2 NADH
+ 4 ATP
PHASE 2
![Page 15: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/15.jpg)
![Page 16: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/16.jpg)
Pyruvate to acetyl CoA
• A carboxyl group is removed from pyruvate (carbon dioxide is produced)
• NADH is produced• acetyl group joins with coenzyme A
forming acetyl CoA• Coenzyme A is made from
pantothenic acid
![Page 17: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/17.jpg)
Pyruvate
acetyl CoA
Coenzyme A
+ NADH
+ CO2
![Page 18: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/18.jpg)
Glycolysis
Krebs Cycle
acetyl CoA
![Page 19: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/19.jpg)
![Page 20: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/20.jpg)
Acetyl Coenzyme A
• Pyruvate is converted into acetyl CoA
• NADH is produced • Carbon dioxide is a waste product• Occurs in the mitochondria
•Yellow- products•Green- reactants
![Page 21: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/21.jpg)
![Page 22: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/22.jpg)
![Page 23: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/23.jpg)
![Page 24: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/24.jpg)
2 pyruvate + 2 NAD+ + 2 CoA ----> 2 acetyl CoA + 2 NADH + 2 carbon dioxide
![Page 25: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/25.jpg)
Citric Acid Cycle• Oxidizes acetyl CoA• Also known as Krebs cycle• Occurs in mitochondria (matrix)• Series of steps ultimately
reforming oxaloacetate• All of the energy of glucose is
carried by NADH and FADH2
![Page 26: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/26.jpg)
Citric Acid Cycle
• Acetyl CoA combines with oxaloacetate, forming citrate
• Citrate undergoes conversions, ultimately re-forming exaloacetate
• Carbon dioxide is a waste product• ATP, NADH, and FADH2 are
produced
![Page 27: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/27.jpg)
Acetyl CoA
oxaloacetate
+ 6 NADH
+ 2 ATP
+ 2 FADH2
![Page 28: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/28.jpg)
One Turn of Citric Acid Cycle*
1. 2C molecule enters the cycle & joins a 4C molecule.
2. In a series of steps, the remaining H and high energy e- are removed from the 2C.
3. 3 NAD+ are converted into 3 NADH & 3H+.
4. 1 FAD is converted into 1 FADH2.5. 1 ATP is made.6. 2 CO2 are released.7. At the end of the cycle, nothing remains
of the original glucose molecule. * remember…this is x2!
![Page 29: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/29.jpg)
![Page 30: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/30.jpg)
![Page 31: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/31.jpg)
![Page 32: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/32.jpg)
![Page 33: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/33.jpg)
![Page 34: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/34.jpg)
![Page 35: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/35.jpg)
![Page 36: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/36.jpg)
![Page 37: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/37.jpg)
Types of Reactions
• Dehydrogenation– Hydrogens are transferred to a
coenzyme (NAD+ or FAD)• Decarboxylations
– Carboxyl groups are removed from the substrate as carbon dioxide
• Preparation reactions– molecules are rearranged in
preparation for decarboxylations or dehydrogenations
![Page 38: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/38.jpg)
Electron Transport SystemChemiosmosis
• Electrons that originated in glucose are transferred via NADH and FADH2 to a chain of electron acceptors
• Hydrogen ions are pumped across the inner mitochondrial membrane
• ATP is produced by chemiosmosis
![Page 39: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/39.jpg)
Electron Transport Chain• Coupled to ATP synthesis• Transports e- from NADH and
FADH2 to O2
Electrons FMN a series of cytochromes and coenzyme Q
![Page 40: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/40.jpg)
Electron Carriers
• Most electron carriers carry hydrogen atoms
• Electron carriers transfer energy• Electrons lose energy as they are
transferred between acceptors• NAD+ is a common hydrogen acceptor
is respiratory and photosynthetic pathways– Nicotinamide adenine dinucleotide
![Page 41: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/41.jpg)
Electron Carriers• Nicotine adenine dinucleotide
phosphate (NADP+) is involved in photosynthesis
![Page 42: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/42.jpg)
![Page 43: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/43.jpg)
NAD+ is a coenzyme derived from the vitamin nicotinic acid (niacin)
![Page 44: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/44.jpg)
Electron Carriers• Flavin Adenine Dinucleotide- FAD+
is involved in cellular respiration
![Page 45: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/45.jpg)
![Page 46: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/46.jpg)
Electron Carriers• Cytochromes- proteins containing
iron
![Page 47: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/47.jpg)
![Page 48: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/48.jpg)
![Page 49: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/49.jpg)
Electron Transport Chain
– Electrons lose energy as they pass through the chain
![Page 50: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/50.jpg)
Electron Transport Chain– Hydrogen ions (protons) are passed
into the intermembrane space of the mitochondria
![Page 51: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/51.jpg)
Electron Transport Chain
– Electrons are finally passed to oxygen thereby forming water
![Page 52: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/52.jpg)
FMN
Q
cyt b
cyt cr
cyt c
cyt a
cyt a3
2H+
2H+
2H+
NADH
FADH 2
O 2 H 2O
Complex I
Complex II
Complex III
![Page 53: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/53.jpg)
![Page 54: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/54.jpg)
![Page 55: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/55.jpg)
![Page 56: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/56.jpg)
![Page 57: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/57.jpg)
Chemiosmotic Model• 1978 Nobel Prize in
Chemistry for a 1961 paper on the chemiosmotic model
• Cornwall, UK• Glynn Research
Laboratories• Died in 1992
Peter Mitchell
![Page 58: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/58.jpg)
Chemiosmotic model
• Explains the coupling of ATP synthesis to electron transport
• A proton gradient is formed across the inner mitochondrial membrane
![Page 59: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/59.jpg)
Chemiosmotic Model
• Protons diffuse through the channels formed by the enzyme complex ATP synthase
• Movement of protons catalyze production of ATP
• Protons diffuse through the channels formed by the enzyme complex ATP synthase
• Movement of protons catalyze production of ATP
![Page 60: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/60.jpg)
![Page 61: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/61.jpg)
http://telstar.ote.cmu.edu/biology/animation/ATPSynthesis/biochem.html
![Page 62: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/62.jpg)
![Page 63: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/63.jpg)
Energy Yield• Efficiency is about 40%; the
rest is disseminated as heat• Maximum yield of ATPs
– from NADH- 3 ATP– from FADH2- 2 ATP
• The NADHs from glycolysis produce fewer ATPs due to the necessity of transport of NADH across the mitochondrial membrane
![Page 64: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/64.jpg)
Energy Yield
The NADHs from glycolysis produce fewer ATPs due to the necessity of transport of NADH across the mitochondrial membrane
36 to 38 ATPs yield
![Page 65: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/65.jpg)
GLUCOSE ATP produced
![Page 66: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/66.jpg)
GLUCOSE
GLYCOLYSIS
2 ATPproduced directly
2 ATP
![Page 67: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/67.jpg)
ACETYL CoA
GLUCOSE
GLYCOLYSIS
2 NADH
2 ATPproduced directly
2 ATP
6 ATPthrough electron transport
+
8 ATP
PYRUVIC ACID
2 NADH
6 ATPthrough electron transport
+
14 ATP
KREBS CYCLE
2 ATPproduced directly
+
16 ATP
6 NADH18 ATP
through electron transport
+
34 ATP
2 FADH24 ATP
through electron transport
+
38 ATP
![Page 68: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/68.jpg)
Other Nutrients• Nutrients other that glucose
provide energy• Humans gain more energy from
oxidation of fatty acids than glucose– Lipids contain 9 kcal per gram– Lipids are broken down and glycerol
enters glycolysis; fatty acids are converted to acetyl CoA and enter the citric acid cycle
![Page 69: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/69.jpg)
Other Nutrients
• Proteins are broken down into amino acids– Amino acids are deaminated (the
amino acids are removed)– The remaining carbon chain
centers at various points– Proteins contain about 4 kcal per
gram
![Page 70: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/70.jpg)
Regulation of Aerobic Respiration
•ATP synthesis continues until ADP stores are depleted
•Enzyme regulation is important•An important regulation point is
phosphofructokinase
![Page 71: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/71.jpg)
PFKPFK is the committed step in glycolysis. Once this step is done then glycolysis will carry through.
PFK is activated by ADP/AMP
PFK is inhibited by
ATP
low pH
citrate groups
![Page 72: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/72.jpg)
Anaerobic Respiration
• Various inorganic substances serve as the final electron acceptor like sulfur
• Yield is only the two ATP molecules from glycolysis
• Seen is some bacteria
![Page 73: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/73.jpg)
Alcoholic Fermentation
• Produces ethanol• Pyruvate is converted to ethanol
to regenerate NAD+• Ethanol is a potentially toxic
waste product • Yeast carry out alcoholic
fermentation when oxygen deprived
![Page 74: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/74.jpg)
![Page 75: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/75.jpg)
Lactate Fermentation
• Bacteria and some fungi carry out lactate fermentation
• Pyruvate is converted to lactate to regenerate NAD+
• Strenuous exercise in mammals results in lactate fermentation as well
![Page 76: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/76.jpg)
![Page 77: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/77.jpg)
![Page 78: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/78.jpg)
![Page 79: Energy Releasing Pathways ATP](https://reader035.fdocuments.net/reader035/viewer/2022081506/56814f1f550346895dbcb049/html5/thumbnails/79.jpg)
http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/index.html