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 _________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 _____________and leaves as _________ Photosynthesis generates _______ and _______________________, which are used in cellular respiration Cells use chemical energy stored in organic molecules to regenerate _______, which powers work © 2011 Pearson Education, Inc.

5. Figure 9.2 Light energy ECOSYSTEM Photosynthesis in chloroplasts Cellular respiration in mitochondria CO 2  H 2 O  O 2 Organic molecules ATP powers most cellular work ATP Heat energy

6. Concept 9.1: Catabolic pathways yield energy by _______________ 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________________ __________________ is a partial degradation of sugars that occurs without O 2 _______________________ consumes organic molecules and O 2 and yields ATP _______________ respiration is similar to aerobic respiration but consumes compounds other than O 2 © 2011 Pearson Education, Inc.

8. ___________________________ 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 ______________ ______________________________________________ © 2011 Pearson Education, Inc.

9. Redox Reactions: Oxidation and Reduction The transfer of ________ during chemical reactions releases energy stored in organic molecules This released energy is ultimately used to synthesize __________ © 2011 Pearson Education, Inc.

10. The Principle of Redox Chemical reactions that transfer electrons between reactants are called oxidation-reduction reactions, or ___________________________ In ___________________, a substance loses electrons, or is oxidized In _________________, 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 ____________ _______________ The electron receptor is called the ___________ ________________ Some redox reactions do not transfer electrons but change the ____________ __________ in covalent bonds An example is the reaction between methane and O 2 © 2011 Pearson Education, Inc.

14. Figure 9.3 Reactants Products Energy Water Carbon dioxide Methane (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 _____________, and O 2 is _____________ © 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 __________, a coenzyme As an electron acceptor, NAD + functions as an __________ _______ during cellular respiration Each _________ (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

19. Figure 9.UN04 Dehydrogenase

20. NADH passes the electrons to the ____________________________________ Unlike an uncontrolled reaction, the electron transport chain passes electrons in a ________ __________________ instead of one explosive reaction _____ pulls electrons down the chain in an energy-yielding tumble The energy yielded is used to regenerate _____ © 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 Free energy, G H 2  1 / 2 O 2 2 H  1 / 2 O 2 H2OH2O H2OH2O 2 H +  2 e  2 e  2 H + ATP Electron transport chain (from food via NADH)

22. The Stages of Cellular Respiration: A Preview Harvesting of energy from glucose has three stages –______________ (breaks down glucose into two molecules of pyruvate) –The ____________________ (completes the breakdown of glucose) –_____________________________ (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 FADH 2 Citric acid cycle Pyruvate oxidation Acetyl CoA Glycolysis Glucose Pyruvate CYTOSOL MITOCHONDRION ATP Substrate-level phosphorylation

26. Figure 9.6-3 Electrons carried via NADH Electrons carried via NADH and FADH 2 Citric acid cycle Pyruvate oxidation Acetyl CoA Glycolysis Glucose Pyruvate Oxidative phosphorylation: electron transport and chemiosmosis CYTOSOL MITOCHONDRION ATP Substrate-level phosphorylation Oxidative phosphorylation

27. The process that generates most of the ATP is called _______________________________ because it is powered by redox reactions © 2011 Pearson Education, Inc.

28. BioFlix: Cellular Respiration

29. Oxidative phosphorylation accounts for almost __________ of the ATP generated by cellular respiration A smaller amount of ATP is formed in glycolysis and the citric acid cycle by ________________ _____________________ For each molecule of glucose degraded to CO 2 and water by respiration, the cell makes up to ___ molecules of ATP © 2011 Pearson Education, Inc.

30. Figure 9.7 Substrate Product ADP P ATP Enzyme

31. Concept 9.2: Glycolysis harvests chemical energy by oxidizing glucose to pyruvate _________________ (“splitting of sugar”) breaks down glucose into two molecules of ___________ Glycolysis occurs in the ______________ and has two major phases –___________________________ phase Glycolysis occurs whether or not ____ is present © 2011 Pearson Education, Inc.

32. 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 H 2 O 2 ATP used 4 ATP formed 2 NADH  2 H + Net Glucose 2 Pyruvate  2 H 2 O 2 ATP 2 NADH  2 H + 2 NAD +  4 e   4 H + 4 ATP formed  2 ATP used

33. Figure 9.9-1 Glycolysis: Energy Investment Phase ATP Glucose Glucose 6-phosphate ADP Hexokinase 1

34. Figure 9.9-2 Glycolysis: Energy Investment Phase ATP Glucose Glucose 6-phosphate Fructose 6-phosphate ADP Hexokinase Phosphogluco- isomerase 12

35. Figure 9.9-3 Glycolysis: Energy Investment Phase ATP Glucose Glucose 6-phosphate Fructose 6-phosphate Fructose 1,6-bisphosphate ADP Hexokinase Phosphogluco- isomerase Phospho- fructokinase 123

36. Figure 9.9-4 Glycolysis: Energy Investment Phase ATP Glucose Glucose 6-phosphate Fructose 6-phosphate Fructose 1,6-bisphosphate Dihydroxyacetone phosphate Glyceraldehyde 3-phosphate To step 6 ADP Hexokinase Phosphogluco- isomerase Phospho- fructokinase Aldolase Isomerase 12345

37. Figure 9.9-5 Glycolysis: Energy Payoff Phase 2 NADH 2 NAD  + 2 H  2 P i 1,3-Bisphospho- glycerate 6 Triose phosphate dehydrogenase

38. 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

39. 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

40. 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 22 2 H 2 O Phospho- glycerokinase Phospho- glyceromutase Enolase 6 7 89 Triose phosphate dehydrogenase

41. Figure 9.9-9 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) Pyruvate 2 ADP 2 22 2 H 2 O Phospho- glycerokinase Phospho- glyceromutase EnolasePyruvate kinase 6 7 8910 Triose phosphate dehydrogenase

42. Concept 9.3: After pyruvate is oxidized, the citric acid cycle completes the energy- yielding oxidation of organic molecules In the presence of O 2, pyruvate enters the ________________ (in eukaryotic cells) where the oxidation of glucose is completed © 2011 Pearson Education, Inc.

43. Oxidation of Pyruvate to Acetyl CoA Before the citric acid cycle can begin, pyruvate must be converted to acetyl Coenzyme A (_______________), which links glycolysis to the citric acid cycle This step is carried out by a ________________ _______________ that catalyses three reactions © 2011 Pearson Education, Inc.

44. Figure 9.10 Pyruvate Transport protein CYTOSOL MITOCHONDRION CO 2 Coenzyme A NAD  + H  NADH Acetyl CoA 123

45. The citric acid cycle, also called the _________ ________, completes the break down of ______________ _____________ The cycle oxidizes organic fuel derived from pyruvate, generating __ ATP, __ NADH, and __ FADH 2 per turn © 2011 Pearson Education, Inc. The Citric Acid Cycle

46. Figure 9.11 Pyruvate NAD  NADH + H  Acetyl CoA CO 2 CoA 2 CO 2 ADP + P i FADH 2 FAD ATP 3 NADH 3 NAD  Citric acid cycle + 3 H 

47. The citric acid cycle has eight steps, each catalyzed by a specific ______________ The acetyl group of acetyl CoA joins the cycle by combining with _________________, forming ________________ The next seven steps decompose the citrate back to oxaloacetate, making the process a cycle The ________ and _________ produced by the cycle relay electrons extracted from food to the electron transport chain © 2011 Pearson Education, Inc.

48. Figure 9.12-1 1 Acetyl CoA Citrate Citric acid cycle CoA-SH Oxaloacetate

49. Figure 9.12-2 1 Acetyl CoA Citrate Isocitrate Citric acid cycle H2OH2O 2 CoA-SH Oxaloacetate

50. Figure 9.12-3 1 Acetyl CoA Citrate Isocitrate  -Ketoglutarate Citric acid cycle NADH + H  NAD  H2OH2O 32 CoA-SH CO2CO2 Oxaloacetate

51. Figure 9.12-4 1 Acetyl CoA Citrate Isocitrate  -Ketoglutarate Succinyl CoA Citric acid cycle NADH + H  NAD  H2OH2O 324 CoA-SH CO2CO2 CO2CO2 Oxaloacetate

52. Figure 9.12-5 1 Acetyl CoA Citrate Isocitrate  -Ketoglutarate Succinyl CoA Succinate Citric acid cycle NADH ATP + H  NAD  H2OH2O ADP GTPGDP P i 3245 CoA-SH CO2CO2 CO2CO2 Oxaloacetate

53. Figure 9.12-6 1 Acetyl CoA Citrate Isocitrate  -Ketoglutarate Succinyl CoA Succinate Fumarate Citric acid cycle NADH FADH 2 ATP + H  NAD  H2OH2O ADP GTPGDP P i FAD 32456 CoA-SH CO2CO2 CO2CO2 Oxaloacetate

54. Figure 9.12-7 1 Acetyl CoA Citrate Isocitrate  -Ketoglutarate Succinyl CoA Succinate Fumarate Malate Citric acid cycle NADH FADH 2 ATP + H  NAD  H2OH2O H2OH2O ADP GTPGDP P i FAD 324567 CoA-SH CO2CO2 CO2CO2 Oxaloacetate

55. Figure 9.12-8 NADH 1 Acetyl CoA Citrate Isocitrate  -Ketoglutarate Succinyl CoA Succinate Fumarate Malate Citric acid cycle NAD  NADH FADH 2 ATP + H  NAD  H2OH2O H2OH2O ADP GTPGDP P i FAD 3245678 CoA-SH CO2CO2 CO2CO2 Oxaloacetate

56. Concept 9.4: During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis Following glycolysis and the citric acid cycle, ________ and ________ account for most of the energy extracted from food These two electron carriers donate electrons to the _________________________, which powers ATP synthesis via ________________ ________________________ © 2011 Pearson Education, Inc.

57. The Pathway of Electron Transport The ____________________ is in the inner membrane (__________) of the mitochondrion Most of the chain’s components are __________, which exist in multiprotein complexes The carriers alternate reduced and oxidized states as they ___________________________ Electrons drop in free energy as they go down the chain and are finally passed to ___, forming ______ © 2011 Pearson Education, Inc.

58. Figure 9.13 NADH FADH 2 2 H  + 1 / 2 O 2 2 e  H2OH2O NAD  Multiprotein complexes (originally from NADH or FADH 2 ) I II III IV 50 40 30 20 10 0 Free energy (G) relative to O 2 (kcal/mol) FMN Fe  S FAD Q Cyt b Cyt c 1 Cyt c Cyt a Cyt a 3 Fe  S

59. Chemiosmosis: The Energy-Coupling Mechanism Electron transfer in the electron transport chain causes proteins to __________ from the mitochondrial matrix to the intermembrane space H + then moves back across the membrane, passing through the proton, ______________ ATP synthase uses the exergonic flow of H + to drive ___________________________ This is an example of _________________, the use of energy in a H + gradient to drive cellular work © 2011 Pearson Education, Inc.

60. Electrons are transferred from ______________ to the electron transport chain Electrons are passed through a number of proteins including ________________ (each with an iron atom) to O 2 The electron transport chain generates _________________________________ It breaks the large free-energy drop from food to O 2 into _____________________ that release energy in manageable amounts © 2011 Pearson Education, Inc.

61. Figure 9.14 INTERMEMBRANE SPACE Rotor Stator HH Internal rod Catalytic knob ADP + P i ATP MITOCHONDRIAL MATRIX

62. 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 FAD FADH 2 NADH ADP  P i NAD  HH 2 H  + 1 / 2 O 2 HH HH HH 21 HH H2OH2O ATP

63. The energy stored in a ______________ across a membrane couples the redox reactions of the electron transport chain to ATP synthesis The H + gradient is referred to as a ___________________________, emphasizing its capacity to do work © 2011 Pearson Education, Inc.

64. Figure 9.16 Electron shuttles span membrane MITOCHONDRION 2 NADH 6 NADH 2 FADH 2 or  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

65. An Accounting of ATP Production by Cellular Respiration During cellular respiration, most energy flows in this sequence: _________  _______  __________________  _______________  _____________ About 34% of the energy in a glucose molecule is transferred to ATP during cellular respiration, making about _________________ There are several reasons why the number of ATP is not known exactly © 2011 Pearson Education, Inc.

66. Concept 9.5: Fermentation and anaerobic respiration enable cells to produce ATP without the use of oxygen Most cellular respiration requires ____ to produce ATP ______________, the electron transport chain will cease to operate In that case, glycolysis couples with ______________________________ to produce ATP © 2011 Pearson Education, Inc.

67. Anaerobic respiration uses an electron transport chain with a final electron acceptor other than O 2, for example _____________ Fermentation uses _____________________ ________________ instead of an electron transport chain to generate ATP © 2011 Pearson Education, Inc.

68. Types of Fermentation Fermentation consists of _______________ plus reactions that __________________, which can be reused by glycolysis Two common types are ________________and __________________________________ © 2011 Pearson Education, Inc.

69. In_______________________, pyruvate is converted to ______________ in two steps, with the first releasing _______ Alcohol fermentation by _____________ is used in brewing, winemaking, and baking © 2011 Pearson Education, Inc.

70. Animation: Fermentation Overview Right-click slide / select “Play”

71. Figure 9.17 2 ADP 2 ATP Glucose Glycolysis 2 Pyruvate 2 CO 2 2  2 NADH 2 Ethanol 2 Acetaldehyde (a) Alcohol fermentation (b) Lactic acid fermentation 2 Lactate 2 Pyruvate 2 NADH Glucose Glycolysis 2 ATP 2 ADP  2 P i NAD 2 H   2 P i 2 NAD    2 H 

72. 2 ADP  2 P i 2 ATP Glucose Glycolysis 2 Pyruvate 2 CO 2 2 NAD  2 NADH 2 Ethanol 2 Acetaldehyde (a) Alcohol fermentation  2 H  Figure 9.17a

73. In ________________________, pyruvate is reduced to NADH, forming ____________ as an end product, with no release of __________ Lactic acid fermentation by some _______ and _____________ is used to make cheese and yogurt Human _________________ use lactic acid fermentation to generate ATP when O 2 is scarce © 2011 Pearson Education, Inc.

74. (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

75. Comparing Fermentation with Anaerobic and Aerobic Respiration All use ____________ (net ATP = 2) to oxidize glucose and harvest chemical energy of food In all three, __________ is the oxidizing agent that accepts electrons during glycolysis The processes have different final electron acceptors: an ____________ _________ (such as pyruvate or acetaldehyde) in fermentation and ___ in cellular respiration Cellular respiration produces ____ ATP per glucose molecule; fermentation produces ____ ATP per glucose molecule © 2011 Pearson Education, Inc.

76. ___________ __________ carry out fermentation or anaerobic respiration and cannot survive in the presence of O 2 Yeast and many bacteria are ___________ __________, meaning that they can survive using either fermentation or cellular respiration In a facultative anaerobe, __________ is a fork in the metabolic road that leads to two alternative catabolic routes © 2011 Pearson Education, Inc.

77. Figure 9.18 Glucose CYTOSOL Glycolysis Pyruvate No O 2 present: Fermentation O 2 present: Aerobic cellular respiration Ethanol, lactate, or other products Acetyl CoA MITOCHONDRION Citric acid cycle

78. The Evolutionary Significance of Glycolysis Ancient _________________ are thought to have used glycolysis long before there was oxygen in the atmosphere Very little O 2 was available in the atmosphere until about 2.7 billion years ago, so early prokaryotes likely used only _____________ to generate ATP _________________ is a very ancient process © 2011 Pearson Education, Inc.

79. 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 ________ and ____________ pathways © 2011 Pearson Education, Inc.

80. The Versatility of Catabolism ____________ _____________ funnel electrons from many kinds of organic molecules into cellular respiration _____________ accepts a wide range of carbohydrates Proteins must be digested to ______________; amino groups can feed __________ or the ____________________________ © 2011 Pearson Education, Inc.

81. _________ are digested to ____________ (used in glycolysis) and _________ ______ (used in generating ___________) Fatty acids are broken down by _____________________ and yield acetyl CoA An oxidized gram of fat produces more than __________ as much ATP as an oxidized gram of carbohydrate © 2011 Pearson Education, Inc.

82. Figure 9.19 Carbohydrates Proteins Fatty acids Amino acids Sugars Fats Glycerol Glycolysis Glucose Glyceraldehyde 3- P NH 3 Pyruvate Acetyl CoA Citric acid cycle Oxidative phosphorylation

83. 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.

84. Regulation of Cellular Respiration via Feedback Mechanisms _________________________ is the most common mechanism for control If _________________________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 ______________at strategic points in the catabolic pathway © 2011 Pearson Education, Inc.

85. Figure 9.20 Phosphofructokinase Glucose Glycolysis AMP Stimulates    Fructose 6-phosphate Fructose 1,6-bisphosphate Pyruvate Inhibits ATPCitrate Citric acid cycle Oxidative phosphorylation Acetyl CoA