Ch 9: Cell Respiration and Fermentation
- 1. LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson © 2011 Pearson Education, Inc. Lectures by Erin Barley Kathleen Fitzpatrick Cellular Respiration and Fermentation Chapter 9
- 2. Overview: Life Is Work • Living cells require energy from outside sources • Some animals, such as the chimpanzee, obtain energy by eating plants, and some animals feed on other organisms that eat plants © 2011 Pearson Education, Inc.
- 3. Figure 9.1
- 4. • Energy flows into an ecosystem as sunlight and leaves as heat • Photosynthesis generates O2 and organic molecules, which are used in cellular respiration • Cells use chemical energy stored in organic molecules to regenerate ATP, which powers work © 2011 Pearson Education, Inc.
- 5. Figure 9.2 Light energy ECOSYSTEM Photosynthesis in chloroplasts Cellular respiration in mitochondria CO2 + H2O + O2 Organic molecules ATP powers most cellular work ATP Heat energy
- 6. Concept 9.1: Catabolic pathways yield energy by oxidizing organic fuels • Several processes are central to cellular respiration and related pathways © 2011 Pearson Education, Inc.
- 7. Catabolic Pathways and Production of ATP • The breakdown of organic molecules is exergonic • Fermentation is a partial degradation of sugars that occurs without O2 • Aerobic respiration consumes organic molecules and O2 and yields ATP • Anaerobic respiration is similar to aerobic respiration but consumes compounds other than O2 © 2011 Pearson Education, Inc.
- 8. • Cellular respiration includes both aerobic and anaerobic respiration but is often used to refer to aerobic respiration • Although carbohydrates, fats, and proteins are all consumed as fuel, it is helpful to trace cellular respiration with the sugar glucose C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy (ATP + heat) © 2011 Pearson Education, Inc.
- 9. Redox Reactions: Oxidation and Reduction • The transfer of electrons during chemical reactions releases energy stored in organic molecules • This released energy is ultimately used to synthesize ATP © 2011 Pearson Education, Inc.
- 10. The Principle of Redox • Chemical reactions that transfer electrons between reactants are called oxidation-reduction reactions, or redox reactions • In oxidation, a substance loses electrons, or is oxidized • In reduction, a substance gains electrons, or is reduced (the amount of positive charge is reduced) © 2011 Pearson Education, Inc.
- 11. Figure 9.UN01 becomes oxidized (loses electron) becomes reduced (gains electron)
- 12. Figure 9.UN02 becomes oxidized becomes reduced
- 13. • The electron donor is called the reducing agent • The electron receptor is called the oxidizing agent • Some redox reactions do not transfer electrons but change the electron sharing in covalent bonds • An example is the reaction between methane and O2 © 2011 Pearson Education, Inc.
- 14. Figure 9.3 Reactants Products Energy WaterCarbon dioxideMethane (reducing agent) Oxygen (oxidizing agent) becomes oxidized becomes reduced
- 15. Oxidation of Organic Fuel Molecules During Cellular Respiration • During cellular respiration, the fuel (such as glucose) is oxidized, and O2 is reduced © 2011 Pearson Education, Inc.
- 16. Figure 9.UN03 becomes oxidized becomes reduced
- 17. Stepwise Energy Harvest via NAD+ and the Electron Transport Chain • In cellular respiration, glucose and other organic molecules are broken down in a series of steps • Electrons from organic compounds are usually first transferred to NAD+ , a coenzyme • As an electron acceptor, NAD+ functions as an oxidizing agent during cellular respiration • Each NADH (the reduced form of NAD+ ) represents stored energy that is tapped to synthesize ATP © 2011 Pearson Education, Inc.
- 18. Figure 9.4 Nicotinamide (oxidized form) NAD+ (from food) Dehydrogenase Reduction of NAD+ Oxidation of NADH Nicotinamide (reduced form) NADH
- 20. • NADH passes the electrons to the electron transport chain • Unlike an uncontrolled reaction, the electron transport chain passes electrons in a series of steps instead of one explosive reaction • O2 pulls electrons down the chain in an energy- yielding tumble • The energy yielded is used to regenerate ATP © 2011 Pearson Education, Inc.
- 21. Figure 9.5 (a) Uncontrolled reaction (b) Cellular respiration Explosive release of heat and light energy Controlled release of energy for synthesis of ATP Freeenergy,G Freeenergy,G H2 + 1 /2 O2 2 H + 1 /2 O2 1 /2 O2 H2O H2O 2 H+ + 2 e− 2 e− 2 H+ ATP ATP ATP Electrontransport chain (from food via NADH)
- 22. The Stages of Cellular Respiration: A Preview • Harvesting of energy from glucose has three stages – Glycolysis (breaks down glucose into two molecules of pyruvate) – The citric acid cycle (completes the breakdown of glucose) – Oxidative phosphorylation (accounts for most of the ATP synthesis) © 2011 Pearson Education, Inc.
- 23. Figure 9.UN05 Glycolysis (color-coded teal throughout the chapter)1. Pyruvate oxidation and the citric acid cycle (color-coded salmon) 2. Oxidative phosphorylation: electron transport and chemiosmosis (color-coded violet) 3.
- 24. Figure 9.6-1 Electrons carried via NADH Glycolysis Glucose Pyruvate CYTOSOL MITOCHONDRION ATP Substrate-level phosphorylation
- 25. Figure 9.6-2 Electrons carried via NADH Electrons carried via NADH and FADH2 Citric acid cycle Pyruvate oxidation Acetyl CoA Glycolysis Glucose Pyruvate CYTOSOL MITOCHONDRION ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation
- 26. Figure 9.6-3 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
- 27. • The process that generates most of the ATP is called oxidative phosphorylation because it is powered by redox reactions © 2011 Pearson Education, Inc. BioFlix: Cellular Respiration
- 28. • Oxidative phosphorylation accounts for almost 90% of the ATP generated by cellular respiration • A smaller amount of ATP is formed in glycolysis and the citric acid cycle by substrate-level phosphorylation • For each molecule of glucose degraded to CO2 and water by respiration, the cell makes up to 32 molecules of ATP © 2011 Pearson Education, Inc.
- 30. Concept 9.2: Glycolysis harvests chemical energy by oxidizing glucose to pyruvate • Glycolysis (“splitting of sugar”) breaks down glucose into two molecules of pyruvate • Glycolysis occurs in the cytoplasm and has two major phases – Energy investment phase – Energy payoff phase • Glycolysis occurs whether or not O2 is present © 2011 Pearson Education, Inc.
- 31. Figure 9.8 Energy Investment Phase Glucose 2 ADP + 2 P 4 ADP + 4 P Energy Payoff Phase 2 NAD+ + 4 e− + 4 H+ 2 Pyruvate + 2 H2O 2 ATP used 4 ATP formed 2 NADH + 2 H+ Net Glucose 2 Pyruvate + 2 H2O 2 ATP 2 NADH + 2 H+ 2 NAD+ + 4 e− + 4 H+ 4 ATP formed − 2 ATP used
- 32. Figure 9.9-1 Glycolysis: Energy Investment Phase ATP Glucose Glucose 6-phosphate ADP Hexokinase 1
- 33. Figure 9.9-2 Glycolysis: Energy Investment Phase ATP Glucose Glucose 6-phosphate Fructose 6-phosphate ADP Hexokinase Phosphogluco- isomerase 1 2
- 34. Figure 9.9-3 Glycolysis: Energy Investment Phase ATP ATP Glucose Glucose 6-phosphate Fructose 6-phosphate Fructose 1,6-bisphosphate ADP ADP Hexokinase Phosphogluco- isomerase Phospho- fructokinase 1 2 3
- 35. Figure 9.9-4 Glycolysis: Energy Investment Phase ATP ATP Glucose Glucose 6-phosphate Fructose 6-phosphate Fructose 1,6-bisphosphate Dihydroxyacetone phosphate Glyceraldehyde 3-phosphate To step 6 ADP ADP Hexokinase Phosphogluco- isomerase Phospho- fructokinase Aldolase Isomerase 1 2 3 4 5
- 36. Figure 9.9-5 Glycolysis: Energy Payoff Phase 2 NADH 2 NAD+ +2 H+ 2 P i 1,3-Bisphospho- glycerate6 Triose phosphate dehydrogenase
- 37. Figure 9.9-6 Glycolysis: Energy Payoff Phase 2 ATP 2 NADH 2 NAD+ +2 H+ 2 P i 2 ADP 1,3-Bisphospho- glycerate 3-Phospho- glycerate 2 Phospho- glycerokinase 6 7 Triose phosphate dehydrogenase
- 38. Figure 9.9-7 Glycolysis: Energy Payoff Phase 2 ATP 2 NADH 2 NAD+ +2 H+ 2 P i 2 ADP 1,3-Bisphospho- glycerate 3-Phospho- glycerate 2-Phospho- glycerate 2 2 Phospho- glycerokinase Phospho- glyceromutase 6 7 8 Triose phosphate dehydrogenase
- 39. Figure 9.9-8 Glycolysis: Energy Payoff Phase 2 ATP 2 NADH 2 NAD+ +2 H+ 2 P i 2 ADP 1,3-Bisphospho- glycerate 3-Phospho- glycerate 2-Phospho- glycerate Phosphoenol- pyruvate (PEP) 2 2 2 2 H2O Phospho- glycerokinase Phospho- glyceromutase Enolase 6 7 8 9 Triose phosphate dehydrogenase
- 40. Figure 9.9-9 Glycolysis: Energy Payoff Phase 2 ATP 2 ATP 2 NADH 2 NAD+ +2 H+ 2 P i 2 ADP 1,3-Bisphospho- glycerate 3-Phospho- glycerate 2-Phospho- glycerate Phosphoenol- pyruvate (PEP) Pyruvate 2 ADP 2 2 2 2 H2O Phospho- glycerokinase Phospho- glyceromutase Enolase Pyruvate kinase 6 7 8 9 10 Triose phosphate dehydrogenase
- 41. Figure 9.9a Glycolysis: Energy Investment Phase ATP Glucose Glucose 6-phosphate ADP Hexokinase 1 Fructose 6-phosphate Phosphogluco- isomerase 2
- 42. Figure 9.9b Glycolysis: Energy Investment Phase ATP Fructose 6-phosphate ADP 3 Fructose 1,6-bisphosphate Phospho- fructokinase 4 5 Aldolase Dihydroxyacetone phosphate Glyceraldehyde 3-phosphate To step 6 Isomerase
- 43. Figure 9.9c Glycolysis: Energy Payoff Phase 2 NADH 2 ATP 2 ADP 2 2 2 NAD+ + 2 H+ 2 P i 3-Phospho- glycerate 1,3-Bisphospho- glycerate Triose phosphate dehydrogenase Phospho- glycerokinase 6 7
- 44. Figure 9.9d Glycolysis: Energy Payoff Phase 2 ATP 2 ADP 2222 2 H2O PyruvatePhosphoenol- pyruvate (PEP) 2-Phospho- glycerate 3-Phospho- glycerate 8 9 10 Phospho- glyceromutase Enolase Pyruvate kinase
- 45. Concept 9.3: After pyruvate is oxidized, the citric acid cycle completes the energy- yielding oxidation of organic molecules • In the presence of O2, pyruvate enters the mitochondrion (in eukaryotic cells) where the oxidation of glucose is completed © 2011 Pearson Education, Inc.
- 46. Oxidation of Pyruvate to Acetyl CoA • Before the citric acid cycle can begin, pyruvate must be converted to acetyl Coenzyme A (acetyl CoA), which links glycolysis to the citric acid cycle • This step is carried out by a multienzyme complex that catalyses three reactions © 2011 Pearson Education, Inc.
- 47. Figure 9.10 Pyruvate Transport protein CYTOSOL MITOCHONDRION CO2 Coenzyme A NAD+ + H+ NADH Acetyl CoA 1 2 3
- 48. • The citric acid cycle, also called the Krebs cycle, completes the break down of pyruvate to CO2 • The cycle oxidizes organic fuel derived from pyruvate, generating 1 ATP, 3 NADH, and 1 FADH2 per turn © 2011 Pearson Education, Inc. The Citric Acid Cycle
- 49. Figure 9.11 Pyruvate NAD+ NADH + H+ Acetyl CoA CO2 CoA CoA CoA 2 CO2 ADP + P i FADH2 FAD ATP 3 NADH 3 NAD+ Citric acid cycle + 3 H+
- 50. • The citric acid cycle has eight steps, each catalyzed by a specific enzyme • The acetyl group of acetyl CoA joins the cycle by combining with oxaloacetate, forming citrate • The next seven steps decompose the citrate back to oxaloacetate, making the process a cycle • The NADH and FADH2 produced by the cycle relay electrons extracted from food to the electron transport chain © 2011 Pearson Education, Inc.
- 53. Figure 9.12-3 1 Acetyl CoA Citrate Isocitrate α-Ketoglutarate Citric acid cycle NADH + H+ NAD+ H2O 3 2 CoA-SH CO2 Oxaloacetate
- 54. Figure 9.12-4 1 Acetyl CoA Citrate Isocitrate α-Ketoglutarate Succinyl CoA Citric acid cycle NADH NADH + H+ + H+ NAD+ NAD+ H2O 3 2 4 CoA-SH CO2 CoA-SH CO2 Oxaloacetate
- 55. Figure 9.12-5 1 Acetyl CoA Citrate Isocitrate α-Ketoglutarate Succinyl CoA Succinate Citric acid cycle NADH NADH ATP + H+ + H+ NAD+ NAD+ H2O ADP GTP GDP P i 3 2 4 5 CoA-SH CO2 CoA-SH CoA-SH CO2 Oxaloacetate
- 56. Figure 9.12-6 1 Acetyl CoA Citrate Isocitrate α-Ketoglutarate Succinyl CoA Succinate Fumarate Citric acid cycle NADH NADH FADH2 ATP + H+ + H+ NAD+ NAD+ H2O ADP GTP GDP P i FAD 3 2 4 5 6 CoA-SH CO2 CoA-SH CoA-SH CO2 Oxaloacetate
- 57. Figure 9.12-7 1 Acetyl CoA Citrate Isocitrate α-Ketoglutarate Succinyl CoA Succinate Fumarate Malate Citric acid cycle NADH NADH FADH2 ATP + H+ + H+ NAD+ NAD+ H2O H2O ADP GTP GDP P i FAD 3 2 4 5 6 7 CoA-SH CO2 CoA-SH CoA-SH CO2 Oxaloacetate
- 58. Figure 9.12-8 NADH 1 Acetyl CoA Citrate Isocitrate α-Ketoglutarate Succinyl CoA Succinate Fumarate Malate Citric acid cycle NAD+ NADH NADH FADH2 ATP + H+ + H+ + H+ NAD+ NAD+ H2O H2O ADP GTP GDP P i FAD 3 2 4 5 6 7 8 CoA-SH CO2 CoA-SH CoA-SH CO2 Oxaloacetate
- 60. Figure 9.12b Isocitrate α-Ketoglutarate Succinyl CoA NADH NADH NAD+ NAD+ + H+ CoA-SH CO2 CO2 3 4 + H+
- 63. Concept 9.4: During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis • Following glycolysis and the citric acid cycle, NADH and FADH2 account for most of the energy extracted from food • These two electron carriers donate electrons to the electron transport chain, which powers ATP synthesis via oxidative phosphorylation © 2011 Pearson Education, Inc.
- 64. The Pathway of Electron Transport • The electron transport chain is in the inner membrane (cristae) of the mitochondrion • Most of the chain’s components are proteins, which exist in multiprotein complexes • The carriers alternate reduced and oxidized states as they accept and donate electrons • Electrons drop in free energy as they go down the chain and are finally passed to O2, forming H2O © 2011 Pearson Education, Inc.
- 65. Figure 9.13 NADH FADH2 2 H+ + 1 /2 O2 2 e− 2 e− 2 e− H2O NAD+ Multiprotein complexes (originally from NADH or FADH2) I II III IV 50 40 30 20 10 0 Freeenergy(G)relativetoO2(kcal/mol) FMN Fe•S Fe•S FAD Q Cyt b Cyt c1 Cyt c Cyt a Cyt a3 Fe•S
- 66. • Electrons are transferred from NADH or FADH2 to the electron transport chain • Electrons are passed through a number of proteins including cytochromes (each with an iron atom) to O2 • The electron transport chain generates no ATP directly • It breaks the large free-energy drop from food to O2 into smaller steps that release energy in manageable amounts © 2011 Pearson Education, Inc.
- 67. Chemiosmosis: The Energy-Coupling Mechanism • Electron transfer in the electron transport chain causes proteins to pump H+ from the mitochondrial matrix to the intermembrane space • H+ then moves back across the membrane, passing through the proton, ATP synthase • ATP synthase uses the exergonic flow of H+ to drive phosphorylation of ATP • This is an example of chemiosmosis, the use of energy in a H+ gradient to drive cellular work © 2011 Pearson Education, Inc.
- 68. Figure 9.14 INTERMEMBRANE SPACE Rotor Stator H+ Internal rod Catalytic knob ADP + P i ATP MITOCHONDRIAL MATRIX
- 69. Figure 9.15 Protein complex of electron carriers (carrying electrons from food) Electron transport chain Oxidative phosphorylation Chemiosmosis ATP synth- ase I II III IV Q Cyt c FADFADH2 NADH ADP + P i NAD+ H+ 2 H+ + 1 /2O2 H+ H+ H+ 21 H+ H2O ATP
- 70. • The energy stored in a H+ gradient across a membrane couples the redox reactions of the electron transport chain to ATP synthesis • The H+ gradient is referred to as a proton- motive force, emphasizing its capacity to do work © 2011 Pearson Education, Inc.
- 71. An Accounting of ATP Production by Cellular Respiration • During cellular respiration, most energy flows in this sequence: glucose → NADH → electron 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 • There are several reasons why the number of ATP is not known exactly © 2011 Pearson Education, Inc.
- 72. Figure 9.16 Electron shuttles span membrane MITOCHONDRION 2 NADH 2 NADH 2 NADH 6 NADH 2 FADH2 2 FADH2 or + 2 ATP+ 2 ATP + about 26 or 28 ATP Glycolysis Glucose 2 Pyruvate Pyruvate oxidation 2 Acetyl CoA Citric acid cycle Oxidative phosphorylation: electron transport and chemiosmosis CYTOSOL Maximum per glucose: About 30 or 32 ATP
- 73. Concept 9.5: Fermentation and anaerobic respiration enable cells to produce ATP without the use of oxygen • 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 © 2011 Pearson Education, Inc.
- 74. • Anaerobic respiration uses an electron transport chain with a final electron acceptor other than O2, for example sulfate • Fermentation uses substrate-level phosphorylation instead of an electron transport chain to generate ATP © 2011 Pearson Education, Inc.
- 75. Types of Fermentation • Fermentation consists of glycolysis plus reactions that regenerate NAD+ , which can be reused by glycolysis • Two common types are alcohol fermentation and lactic acid fermentation © 2011 Pearson Education, Inc.
- 76. • In alcohol fermentation, pyruvate is converted to ethanol in two steps, with the first releasing CO2 • Alcohol fermentation by yeast is used in brewing, winemaking, and baking © 2011 Pearson Education, Inc. Animation: Fermentation Overview
- 77. Figure 9.17 2 ADP 2 ATP Glucose Glycolysis 2 Pyruvate 2 CO2 2 + 2 NADH 2 Ethanol 2 Acetaldehyde (a) Alcohol fermentation (b) Lactic acid fermentation 2 Lactate 2 Pyruvate 2 NADH Glucose Glycolysis 2 ATP2 ADP+ 2 P i NAD 2 H+ + 2 P i 2 NAD++ + 2 H+
- 78. 2 ADP + 2 P i 2 ATP Glucose Glycolysis 2 Pyruvate 2 CO2 2 NAD + 2 NADH 2 Ethanol 2 Acetaldehyde (a) Alcohol fermentation + 2 H+ Figure 9.17a
- 79. • In lactic acid fermentation, pyruvate is reduced to NADH, forming lactate as an end product, with no release of CO2 • Lactic acid fermentation 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 © 2011 Pearson Education, Inc.
- 80. (b) Lactic acid fermentation 2 Lactate 2 Pyruvate 2 NADH Glucose Glycolysis 2 ADP + 2 P i 2 ATP 2 NAD + + 2 H+ Figure 9.17b
- 81. Comparing Fermentation with Anaerobic and Aerobic Respiration • All use glycolysis (net ATP = 2) to oxidize glucose and harvest chemical energy of food • In all three, NAD+ is the oxidizing agent that accepts electrons during glycolysis • The processes have different final electron acceptors: an organic molecule (such as pyruvate or acetaldehyde) in fermentation and O2 in cellular respiration • Cellular respiration produces 32 ATP per glucose molecule; fermentation produces 2 ATP per glucose molecule © 2011 Pearson Education, Inc.
- 82. • Obligate anaerobes carry out fermentation or anaerobic respiration and cannot survive in the presence of O2 • Yeast and many bacteria are facultative anaerobes, meaning that they can survive using either fermentation or cellular respiration • In a facultative anaerobe, pyruvate is a fork in the metabolic road that leads to two alternative catabolic routes © 2011 Pearson Education, Inc.
- 83. Figure 9.18 Glucose CYTOSOL Glycolysis Pyruvate No O2 present: Fermentation O2 present: Aerobic cellular respiration Ethanol, lactate, or other products Acetyl CoA MITOCHONDRION Citric acid cycle
- 84. The Evolutionary Significance of Glycolysis • Ancient prokaryotes are thought to have used glycolysis long before there was oxygen in the atmosphere • Very little O2 was available in the atmosphere until about 2.7 billion years ago, so early prokaryotes likely used only glycolysis to generate ATP • Glycolysis is a very ancient process © 2011 Pearson Education, Inc.
- 85. Concept 9.6: Glycolysis and the citric acid cycle connect to many other metabolic pathways • Gycolysis and the citric acid cycle are major intersections to various catabolic and anabolic pathways © 2011 Pearson Education, Inc.
- 86. The Versatility of Catabolism • Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration • Glycolysis accepts a wide range of carbohydrates • Proteins must be digested to amino acids; amino groups can feed glycolysis or the citric acid cycle © 2011 Pearson Education, Inc.
- 87. • Fats are digested to glycerol (used in glycolysis) and fatty acids (used in generating acetyl CoA) • Fatty acids are broken down by beta oxidation and yield acetyl CoA • An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate © 2011 Pearson Education, Inc.
- 88. Figure 9.19 CarbohydratesProteins Fatty acids Amino acids Sugars Fats Glycerol Glycolysis Glucose Glyceraldehyde 3- P NH3 Pyruvate Acetyl CoA Citric acid cycle Oxidative phosphorylation
- 89. Biosynthesis (Anabolic Pathways) • The body uses small molecules to build other substances • These small molecules may come directly from food, from glycolysis, or from the citric acid cycle © 2011 Pearson Education, Inc.
- 90. Regulation of Cellular Respiration via Feedback Mechanisms • Feedback inhibition is the most common mechanism for control • If ATP concentration begins to drop, respiration speeds up; when there is plenty of ATP, respiration slows down • Control of catabolism is based mainly on regulating the activity of enzymes at strategic points in the catabolic pathway © 2011 Pearson Education, Inc.
- 91. Figure 9.20 Phosphofructokinase Glucose Glycolysis AMP Stimulates − − + Fructose 6-phosphate Fructose 1,6-bisphosphate Pyruvate Inhibits Inhibits ATP Citrate Citric acid cycle Oxidative phosphorylation Acetyl CoA
- 92. Figure 9.UN06 Inputs Outputs Glucose Glycolysis 2 Pyruvate + 2 ATP + 2 NADH
- 93. Figure 9.UN07 Inputs Outputs 2 Pyruvate 2 Acetyl CoA 2 Oxaloacetate Citric acid cycle 2 26 8ATP NADH FADH2 CO2
- 94. Figure 9.UN08 Protein complex of electron carriers (carrying electrons from food) INTERMEMBRANE SPACE MITOCHONDRIAL MATRIX H+ H+ H+ 2 H+ + 1 /2 O2 H2O NAD+ FADH2 FAD Q NADH I II III IV Cyt c
- 95. Figure 9.UN09 INTER- MEMBRANE SPACE H+ADP + P i MITO- CHONDRIAL MATRIX ATP synthase H+ ATP
- 97. Figure 9.UN11
Editor's Notes
- #3: For the Discovery Video Space Plants, go to Animation and Video Files.
- #4: Figure 9.1 How do these leaves power the work of life for this chimpanzee?
- #6: Figure 9.2 Energy flow and chemical recycling in ecosystems.
- #12: Figure 9.UN01 In-text figure, p. 164
- #13: Figure 9.UN02 In-text figure, p. 164
- #15: Figure 9.3 Methane combustion as an energy-yielding redox reaction.
- #17: Figure 9.UN03 In-text figure, p. 165
- #19: Figure 9.4 NAD as an electron shuttle.
- #20: Figure 9.UN04 In-text figure, p. 166
- #22: Figure 9.5 An introduction to electron transport chains.
- #24: Figure 9.UN05 In-text figure, p. 167
- #25: Figure 9.6 An overview of cellular respiration.
- #26: Figure 9.6 An overview of cellular respiration.
- #27: Figure 9.6 An overview of cellular respiration.
- #30: Figure 9.7 Substrate-level phosphorylation.
- #32: Figure 9.8 The energy input and output of glycolysis.
- #33: Figure 9.9 A closer look at glycolysis.
- #34: Figure 9.9 A closer look at glycolysis.
- #35: Figure 9.9 A closer look at glycolysis.
- #36: Figure 9.9 A closer look at glycolysis.
- #37: Figure 9.9 A closer look at glycolysis.
- #38: Figure 9.9 A closer look at glycolysis.
- #39: Figure 9.9 A closer look at glycolysis.
- #40: Figure 9.9 A closer look at glycolysis.
- #41: Figure 9.9 A closer look at glycolysis.
- #42: Figure 9.9 A closer look at glycolysis.
- #43: Figure 9.9 A closer look at glycolysis.
- #44: Figure 9.9 A closer look at glycolysis.
- #45: Figure 9.9 A closer look at glycolysis.
- #48: Figure 9.10 Oxidation of pyruvate to acetyl CoA, the step before the citric acid cycle.
- #50: Figure 9.11 An overview of pyruvate oxidation and the citric acid cycle.
- #52: Figure 9.12 A closer look at the citric acid cycle.
- #53: Figure 9.12 A closer look at the citric acid cycle.
- #54: Figure 9.12 A closer look at the citric acid cycle.
- #55: Figure 9.12 A closer look at the citric acid cycle.
- #56: Figure 9.12 A closer look at the citric acid cycle.
- #57: Figure 9.12 A closer look at the citric acid cycle.
- #58: Figure 9.12 A closer look at the citric acid cycle.
- #59: Figure 9.12 A closer look at the citric acid cycle.
- #60: Figure 9.12 A closer look at the citric acid cycle.
- #61: Figure 9.12 A closer look at the citric acid cycle.
- #62: Figure 9.12 A closer look at the citric acid cycle.
- #63: Figure 9.12 A closer look at the citric acid cycle.
- #64: For the Cell Biology Video ATP Synthase 3D Structure — Side View, go to Animation and Video Files. For the Cell Biology Video ATP Synthase 3D Structure — Top View, go to Animation and Video Files.
- #66: Figure 9.13 Free-energy change during electron transport.
- #69: Figure 9.14 ATP synthase, a molecular mill.
- #70: Figure 9.15 Chemiosmosis couples the electron transport chain to ATP synthesis.
- #73: Figure 9.16 ATP yield per molecule of glucose at each stage of cellular respiration.
- #78: Figure 9.17 Fermentation.
- #79: Figure 9.17 Fermentation.
- #81: Figure 9.17 Fermentation.
- #84: Figure 9.18 Pyruvate as a key juncture in catabolism.
- #89: Figure 9.19 The catabolism of various molecules from food.
- #92: Figure 9.20 The control of cellular respiration.
- #93: Figure 9.UN06 Summary figure, Concept 9.2
- #94: Figure 9.UN07 Summary figure, Concept 9.3
- #95: Figure 9.UN08 Summary figure, Concept 9.4 (part 1)
- #96: Figure 9.UN09 Summary figure, Concept 9.4 (part 2)
- #97: Figure 9.UN10 Test Your Understanding, question 8
- #98: Figure 9.UN11 Appendix A: answer to Test Your Understanding, question 8