1. Chapter 9 Cellular Respiration: Harvesting Chemical Energy

4. LE 9-2 ECOSYSTEM Light energy Photosynthesis in chloroplasts Cellular respiration in mitochondria Organic molecules + O 2 CO 2 + H 2 O ATP powers most cellular work Heat energy

11. LE 9-3 Reactants becomes oxidized becomes reduced Products H Methane (reducing agent) Oxygen (oxidizing agent) Carbon dioxide Water H C H H O O O O C O H H CH 4 2 O 2 + + + CO 2 Energy 2 H 2 O

14. LE 9-4 NAD + Nicotinamide (oxidized form) Dehydrogenase 2 e – + 2 H + 2 e – + H + NADH H + H + Nicotinamide (reduced form) + 2[ H ] (from food) +

16. LE 9-5 2 H + + 2 e – 2 H (from food via NADH) Controlled release of energy for synthesis of ATP ATP ATP ATP 2 H + 2 e – H 2 O + 1 / 2 O 2 1 / 2 O 2 H 2 + 1 / 2 O 2 H 2 O Explosive release of heat and light energy Cellular respiration Uncontrolled reaction Free energy, G Free energy, G Electron transport chain

18. LE 9-6_1 Mitochondrion Glycolysis Pyruvate Glucose Cytosol ATP Substrate-level phosphorylation

19. LE 9-6_2 Mitochondrion Glycolysis Pyruvate Glucose Cytosol ATP Substrate-level phosphorylation ATP Substrate-level phosphorylation Citric acid cycle

20. LE 9-6_3 Mitochondrion Glycolysis Pyruvate Glucose Cytosol ATP Substrate-level phosphorylation ATP Substrate-level phosphorylation Citric acid cycle ATP Oxidative phosphorylation Oxidative phosphorylation: electron transport and chemiosmosis Electrons carried via NADH Electrons carried via NADH and FADH 2

22. LE 9-7 Enzyme ADP P Substrate Product Enzyme ATP +

24. LE 9-8 Energy investment phase Glucose 2 ATP used 2 ADP + 2 P 4 ADP + 4 P 4 ATP formed 2 NAD + + 4 e – + 4 H + Energy payoff phase + 2 H + 2 NADH 2 Pyruvate + 2 H 2 O 2 Pyruvate + 2 H 2 O 2 ATP 2 NADH + 2 H + Glucose 4 ATP formed – 2 ATP used 2 NAD+ + 4 e – + 4 H + Net Glycolysis Citric acid cycle Oxidative phosphorylation ATP ATP ATP

25. LE 9-9a_1 Glucose ATP ADP Hexokinase ATP ATP ATP Glycolysis Oxidation phosphorylation Citric acid cycle Glucose-6-phosphate

26. LE 9-9a_2 Glucose ATP ADP Hexokinase ATP ATP ATP Glycolysis Oxidation phosphorylation Citric acid cycle Glucose-6-phosphate Phosphoglucoisomerase Phosphofructokinase Fructose-6-phosphate ATP ADP Fructose- 1, 6-bisphosphate Aldolase Isomerase Dihydroxyacetone phosphate Glyceraldehyde- 3-phosphate

27. LE 9-9b_1 2 NAD + Triose phosphate dehydrogenase + 2 H + NADH 2 1, 3-Bisphosphoglycerate 2 ADP 2 ATP Phosphoglycerokinase Phosphoglyceromutase 2-Phosphoglycerate 3-Phosphoglycerate

28. LE 9-9b_2 2 NAD + Triose phosphate dehydrogenase + 2 H + NADH 2 1, 3-Bisphosphoglycerate 2 ADP 2 ATP Phosphoglycerokinase Phosphoglyceromutase 2-Phosphoglycerate 3-Phosphoglycerate 2 ADP 2 ATP Pyruvate kinase 2 H 2 O Enolase Phosphoenolpyruvate Pyruvate The thing to remember about all of these reactions is that in a series of well-controlled chemical reactions Glucose is converted to Pyruvate

35. LE 9-10 CYTOSOL Pyruvate NAD + MITOCHONDRION Transport protein NADH + H + Coenzyme A CO 2 Acetyl Co A

37. LE 9-11 Pyruvate (from glycolysis, 2 molecules per glucose) ATP ATP ATP Glycolysis Oxidation phosphorylation Citric acid cycle NAD + NADH + H + CO 2 CoA Acetyl CoA CoA CoA Citric acid cycle CO 2 2 3 NAD + + 3 H + NADH 3 ATP ADP + P i FADH 2 FAD

39. LE 9-12_1 ATP ATP ATP Glycolysis Oxidation phosphorylation Citric acid cycle Citric acid cycle Citrate Isocitrate Oxaloacetate Acetyl CoA H 2 O

40. LE 9-12_2 ATP ATP ATP Glycolysis Oxidation phosphorylation Citric acid cycle Citric acid cycle Citrate Isocitrate Oxaloacetate Acetyl CoA H 2 O C O 2 NAD + NADH + H +  -Ketoglutarate C O 2 NAD + NADH + H + Succinyl CoA

41. LE 9-12_3 ATP ATP ATP Glycolysis Oxidation phosphorylation Citric acid cycle Citric acid cycle Citrate Isocitrate Oxaloacetate Acetyl CoA H 2 O C O 2 NAD + NADH + H +  -Ketoglutarate C O 2 NAD + NADH + H + Succinyl CoA Succinate GTP GDP ADP ATP FAD FADH 2 P i Fumarate

42. LE 9-12_4 ATP ATP ATP Glycolysis Oxidation phosphorylation Citric acid cycle Citric acid cycle Citrate Isocitrate Oxaloacetate Acetyl CoA H 2 O C O 2 NAD + NADH + H +  -Ketoglutarate C O 2 NAD + NADH + H + Succinyl CoA Succinate GTP GDP ADP ATP FAD FADH 2 P i Fumarate H 2 O Malate NAD + NADH + H +

45. LE 9-13 ATP ATP ATP Glycolysis Oxidative phosphorylation: electron transport and chemiosmosis Citric acid cycle NADH 50 FADH 2 40 FMN Fe•S I FAD Fe•S II III Q Fe•S Cyt b 30 20 Cyt c Cyt c 1 Cyt a Cyt a 3 IV 10 0 Multiprotein complexes Free energy ( G ) relative to O2 (kcal/mol) H 2 O O 2 2 H + + 1 / 2

48. LE 9-14 INTERMEMBRANE SPACE H + H + H + H + H + H + H + H + ATP MITOCHONDRAL MATRIX ADP + P i A rotor within the membrane spins as shown when H + flows past it down the H + gradient. A stator anchored in the membrane holds the knob stationary. A rod (or “stalk”) extending into the knob also spins, activating catalytic sites in the knob. Three catalytic sites in the stationary knob join inorganic phosphate to ADP to make ATP. Comparison of the ETC to an electric motor

50. LE 9-15 Protein complex of electron carriers H + ATP ATP ATP Glycolysis Oxidative phosphorylation: electron transport and chemiosmosis Citric acid cycle H + Q III I II FAD FADH 2 + H + NADH NAD + (carrying electrons from food) Inner mitochondrial membrane Inner mitochondrial membrane Mitochondrial matrix Intermembrane space H + H + Cyt c IV 2H + + 1 / 2 O 2 H 2 O ADP + H + ATP ATP synthase ETC: Electron transport and pumping of protons (H + ), Which create an H + gradient across the membrane P i Chemiosmosis ATP synthesis powered by the flow of H + back across the membrane Oxidative phosphorylation

52. LE 9-16 CYTOSOL Electron shuttles span membrane 2 NADH or 2 FADH 2 MITOCHONDRION Oxidative phosphorylation: electron transport and chemiosmosis 2 FADH 2 2 NADH 6 NADH Citric acid cycle 2 Acetyl CoA 2 NADH Glycolysis Glucose 2 Pyruvate + 2 ATP by substrate-level phosphorylation + 2 ATP by substrate-level phosphorylation + about 32 or 34 ATP by oxidation phosphorylation, depending on which shuttle transports electrons form NADH in cytosol About 36 or 38 ATP Maximum per glucose:

56. LE 9-17a CO 2 + 2 H + 2 NADH 2 NAD + 2 Acetaldehyde 2 ATP 2 ADP + 2 P i 2 Pyruvate 2 2 Ethanol Alcohol fermentation Glucose Glycolysis

58. LE 9-17b CO 2 + 2 H + 2 NADH 2 NAD + 2 ATP 2 ADP + 2 P i 2 Pyruvate 2 2 Lactate Lactic acid fermentation Glucose Glycolysis

61. LE 9-18 Pyruvate Glucose CYTOSOL No O 2 present Fermentation Ethanol or lactate Acetyl CoA MITOCHONDRION O 2 present Cellular respiration Citric acid cycle

65. LE 9-19 Citric acid cycle Oxidative phosphorylation Proteins NH 3 Amino acids Sugars Carbohydrates Glycolysis Glucose Glyceraldehyde-3- P Pyruvate Acetyl CoA Fatty acids Glycerol Fats

68. LE 9-20 Citric acid cycle Oxidative phosphorylation Glycolysis Glucose Pyruvate Acetyl CoA Fructose-6-phosphate Phosphofructokinase Fructose-1,6-bisphosphate – Inhibits ATP Citrate Inhibits Stimulates AMP + –