1. © 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko PowerPoint Lectures for Campbell Biology: Concepts & Connections, Seventh Edition Reece, Taylor, Simon, and Dickey Chapter 6 How Cells Harvest Chemical Energy

2. Introduction  In eukaryotes, cellular respiration –harvests energy from food, –yields large amounts of ATP, and –Uses ATP to drive cellular work.  A similar process takes place in many prokaryotic organisms. © 2012 Pearson Education, Inc.

3. Figure 6.0_1 Chapter 6: Big Ideas Cellular Respiration: Aerobic Harvesting of Energy Stages of Cellular Respiration Fermentation: Anaerobic Harvesting of Energy Connections Between Metabolic Pathways

4. Figure 6.0_2

5. CELLULAR RESPIRATION: AEROBIC HARVESTING OF ENERGY © 2012 Pearson Education, Inc.

6. 6.1 Photosynthesis and cellular respiration provide energy for life  Life requires energy.  In almost all ecosystems, energy ultimately comes from the sun.  In photosynthesis, –some of the energy in sunlight is captured by chloroplasts, –atoms of carbon dioxide and water are rearranged, and –glucose and oxygen are produced. © 2012 Pearson Education, Inc.

7. 6.1 Photosynthesis and cellular respiration provide energy for life  In cellular respiration –glucose is broken down to carbon dioxide and water and –the cell captures some of the released energy to make ATP.  Cellular respiration takes place in the mitochondria of eukaryotic cells. © 2012 Pearson Education, Inc.

8. Figure 6.1 Sunlight energy ECOSYSTEM Photosynthesis in chloroplasts Cellular respiration in mitochondria (for cellular work) Heat energy Glucose CO 2 H2OH2O O2O2 ATP

9. Figure 6.1_1 Sunlight energy ECOSYSTEM Photosynthesis in chloroplasts Cellular respiration in mitochondria (for cellular work) Heat energy Glucose CO 2 H2OH2O O2O2 ATP

10. Figure 6.1_2

11. 6.2 Breathing supplies O 2 for use in cellular respiration and removes CO 2  Respiration, as it relates to breathing, and cellular respiration are not the same. –Respiration, in the breathing sense, refers to an exchange of gases. Usually an organism brings in oxygen from the environment and releases waste CO 2. –Cellular respiration is the aerobic (oxygen requiring) harvesting of energy from food molecules by cells. © 2012 Pearson Education, Inc.

12. Figure 6.2 Breathing Lungs Bloodstream CO 2 O2O2 O2O2 Muscle cells carrying out Cellular Respiration Glucose  O 2 CO 2  H 2 O  ATP

13. Figure 6.2_1 Breathing Lungs Bloodstream CO 2 Muscle cells carrying out Cellular Respiration Glucose  O 2 CO 2  H 2 O  ATP CO 2 O2O2 O2O2

14. Figure 6.2_2

15. 6.3 Cellular respiration banks energy in ATP molecules  Cellular respiration is an exergonic process that transfers energy from the bonds in glucose to form ATP.  Cellular respiration –produces up to 32 ATP molecules from each glucose molecule and –captures only about 34% of the energy originally stored in glucose.  Other foods (organic molecules) can also be used as a source of energy. © 2012 Pearson Education, Inc.

16. Figure 6.3 Glucose OxygenWater Carbon dioxide C 6 H 12 O 6 O2O2 H2OH2O ATP6 6 6  Heat CO 2

17. 6.4 CONNECTION: The human body uses energy from ATP for all its activities  The average adult human needs about 2,200 kcal of energy per day. –About 75% of these calories are used to maintain a healthy body. –The remaining 25% is used to power physical activities. © 2012 Pearson Education, Inc.

18. 6.4 CONNECTION: The human body uses energy from ATP for all its activities  A kilocalorie (kcal) is –the quantity of heat required to raise the temperature of 1 kilogram (kg) of water by 1 o C, –the same as a food Calorie, and –used to measure the nutritional values indicated on food labels. © 2012 Pearson Education, Inc.

19. Figure 6.4 Activity kcal consumed per hour by a 67.5-kg (150-lb) person* Running (8–9 mph) Dancing (fast) Bicycling (10 mph) Swimming (2 mph) Walking (4 mph) Walking (3 mph) Dancing (slow) Driving a car Sitting (writing) *Not including kcal needed for body maintenance 979 510 490 408 341 245 204 61 28

20. Figure 6.4_1 Activity kcal consumed per hour by a 67.5-kg (150-lb) person* Running (8–9 mph) Dancing (fast) Bicycling (10 mph) Swimming (2 mph) Walking (4 mph) Walking (3 mph) Dancing (slow) Driving a car Sitting (writing) *Not including kcal needed for body maintenance 979 510 490 408 341 245 204 61 28

21. Figure 6.4_2

22. 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  The energy necessary for life is contained in the arrangement of electrons in chemical bonds in organic molecules.  An important question is how do cells extract this energy? © 2012 Pearson Education, Inc.

23. 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  When the carbon-hydrogen bonds of glucose are broken, electrons are transferred to oxygen. –Oxygen has a strong tendency to attract electrons. –An electron loses potential energy when it “falls” to oxygen. © 2012 Pearson Education, Inc.

24. 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  Energy can be released from glucose by simply burning it.  The energy is dissipated as heat and light and is not available to living organisms. © 2012 Pearson Education, Inc.

25. 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  On the other hand, cellular respiration is the controlled breakdown of organic molecules.  Energy is –gradually released in small amounts, –captured by a biological system, and –stored in ATP. © 2012 Pearson Education, Inc.

26. 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  The movement of electrons from one molecule to another is an oxidation-reduction reaction, or redox reaction. In a redox reaction, –the loss of electrons from one substance is called oxidation, –the addition of electrons to another substance is called reduction, –a molecule is oxidized when it loses one or more electrons, and –reduced when it gains one or more electrons. © 2012 Pearson Education, Inc.

27. 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  A cellular respiration equation is helpful to show the changes in hydrogen atom distribution.  Glucose –loses its hydrogen atoms and –becomes oxidized to CO 2.  Oxygen –gains hydrogen atoms and –becomes reduced to H 2 O. © 2012 Pearson Education, Inc.

28. Figure 6.5A Glucose  Heat C 6 H 12 O 6 O2O2 CO 2 H2OH2O ATP 6 6 6 Loss of hydrogen atoms (becomes oxidized) Gain of hydrogen atoms (becomes reduced)

29. 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  Enzymes are necessary to oxidize glucose and other foods.  NAD + –is an important enzyme in oxidizing glucose, –accepts electrons, and –becomes reduced to NADH. © 2012 Pearson Education, Inc.

30. Figure 6.5B Becomes oxidized Becomes reduced 2H NAD  NADH HH HH 2 2 (carries 2 electrons)

31. 6.5 Cells tap energy from electrons “falling” from organic fuels to oxygen  There are other electron “carrier” molecules that function like NAD +. –They form a staircase where the electrons pass from one to the next down the staircase. –These electron carriers collectively are called the electron transport chain. –As electrons are transported down the chain, ATP is generated. © 2012 Pearson Education, Inc.

32. Figure 6.5C Controlled release of energy for synthesis of ATP NADH NAD  HH HH O2O2 H2OH2O 2 2 2 ATP Electron transport chain 2 1

33. STAGES OF CELLULAR RESPIRATION © 2012 Pearson Education, Inc.

34. 6.6 Overview: Cellular respiration occurs in three main stages  Cellular respiration consists of a sequence of steps that can be divided into three stages. –Stage 1 – Glycolysis –Stage 2 – Pyruvate oxidation and citric acid cycle –Stage 3 – Oxidative phosphorylation © 2012 Pearson Education, Inc.

35. 6.6 Overview: Cellular respiration occurs in three main stages  Stage 1: Glycolysis –occurs in the cytoplasm, –begins cellular respiration, and –breaks down glucose into two molecules of a three- carbon compound called pyruvate. © 2012 Pearson Education, Inc.

36. 6.6 Overview: Cellular respiration occurs in three main stages  Stage 2: The citric acid cycle –takes place in mitochondria, –oxidizes pyruvate to a two-carbon compound, and –supplies the third stage with electrons. © 2012 Pearson Education, Inc.

37. 6.6 Overview: Cellular respiration occurs in three main stages  Stage 3: Oxidative phosphorylation –involves electrons carried by NADH and FADH 2, –shuttles these electrons to the electron transport chain embedded in the inner mitochondrial membrane, –involves chemiosmosis, and –generates ATP through oxidative phosphorylation associated with chemiosmosis. © 2012 Pearson Education, Inc.

38. Figure 6.6 NADH FADH 2 ATP CYTOPLASM Glycolysis Electrons carried by NADH Glucose Pyruvate Pyruvate Oxidation Citric Acid Cycle Oxidative Phosphorylation (electron transport and chemiosmosis) Mitochondrion Substrate-level phosphorylation Oxidative phosphorylation

39. Figure 6.6_1 NADH FADH 2 ATP CYTOPLASM Glycolysis Electrons carried by NADH Glucose Pyruvate Pyruvate Oxidation Citric Acid Cycle Oxidative Phosphorylation (electron transport and chemiosmosis) Mitochondrion Substrate-level phosphorylation Oxidative phosphorylation

40. 6.7 Glycolysis harvests chemical energy by oxidizing glucose to pyruvate  In glycolysis, –a single molecule of glucose is enzymatically cut in half through a series of steps, –two molecules of pyruvate are produced, –two molecules of NAD + are reduced to two molecules of NADH, and –a net of two molecules of ATP is produced. © 2012 Pearson Education, Inc.

41. Figure 6.7A Glucose 2 Pyruvate 2 ADP 2 P 2 NAD  2 NADH 2 H  ATP 2

42. 6.7 Glycolysis harvests chemical energy by oxidizing glucose to pyruvate  ATP is formed in glycolysis by substrate-level phosphorylation during which –an enzyme transfers a phosphate group from a substrate molecule to ADP and –ATP is formed.  The compounds that form between the initial reactant, glucose, and the final product, pyruvate, are called intermediates. © 2012 Pearson Education, Inc.

43. Figure 6.7B Enzyme P P ADP P ATP Substrate Product

44. 6.7 Glycolysis harvests chemical energy by oxidizing glucose to pyruvate  The steps of glycolysis can be grouped into two main phases. –In steps 1–4, the energy investment phase, –energy is consumed as two ATP molecules are used to energize a glucose molecule, –which is then split into two small sugars that are now primed to release energy. –In steps 5–9, the energy payoff, –two NADH molecules are produced for each initial glucose molecule and –ATP molecules are generated. © 2012 Pearson Education, Inc.

45. Figure 6.7Ca_s1 Glucose Glucose 6-phosphate Fructose 6-phosphate Fructose 1,6-bisphosphate ENERGY INVESTMENT PHASE PP P P ADP ATP Step Steps – A fuel molecule is energized, using ATP. 3 3 2 11

46. Figure 6.7Ca_s2 Glucose Glucose 6-phosphate Fructose 6-phosphate Fructose 1,6-bisphosphate Glyceraldehyde 3-phosphate (G3P) ENERGY INVESTMENT PHASE P P PP P P ADP ATP Step Steps – A fuel molecule is energized, using ATP. Step A six-carbon intermediate splits into two three-carbon intermediates. 44 3 3 2 11

47. Figure 6.7Cb_s1 555 Step A redox reaction generates NADH. ENERGY PAYOFF PHASE 1,3-Bisphospho- glycerate NADH NAD  HH HH P P P P P P P P

48. Figure 6.7Cb_s2 6 66555 9 998877 Step A redox reaction generates NADH. Steps – ATP and pyruvate are produced. ENERGY PAYOFF PHASE 1,3-Bisphospho- glycerate 3-Phospho- glycerate 2-Phospho- glycerate Phosphoenol- pyruvate (PEP) Pyruvate NADH NAD  HH HH ADP ATP H2OH2O H2OH2O P P P P P P P P P P P P P P

49. 6.8 Pyruvate is oxidized prior to the citric acid cycle  The pyruvate formed in glycolysis is transported from the cytoplasm into a mitochondrion where –the citric acid cycle and –oxidative phosphorylation will occur. © 2012 Pearson Education, Inc.

50. 6.8 Pyruvate is oxidized prior to the citric acid cycle  Two molecules of pyruvate are produced for each molecule of glucose that enters glycolysis.  Pyruvate does not enter the citric acid cycle, but undergoes some chemical grooming in which –a carboxyl group is removed and given off as CO 2, –the two-carbon compound remaining is oxidized while a molecule of NAD + is reduced to NADH, –coenzyme A joins with the two-carbon group to form acetyl coenzyme A, abbreviated as acetyl CoA, and –acetyl CoA enters the citric acid cycle. © 2012 Pearson Education, Inc.

51. Figure 6.8 Pyruvate Coenzyme A Acetyl coenzyme A NAD  NADHHH CoA CO 2 3 2 1

52. 6.9 The citric acid cycle completes the oxidation of organic molecules, generating many NADH and FADH 2 molecules  The citric acid cycle –is also called the Krebs cycle (after the German-British researcher Hans Krebs, who worked out much of this pathway in the 1930s), –completes the oxidation of organic molecules, and –generates many NADH and FADH 2 molecules. © 2012 Pearson Education, Inc.

53. Figure 6.9A Acetyl CoA Citric Acid Cycle CoA CO 2 2 3 3 NAD  3 H  NADH ADP ATP P FAD FADH 2

54. 6.9 The citric acid cycle completes the oxidation of organic molecules, generating many NADH and FADH 2 molecules  During the citric acid cycle –the two-carbon group of acetyl CoA is added to a four- carbon compound, forming citrate, –citrate is degraded back to the four-carbon compound, –two CO 2 are released, and –1 ATP, 3 NADH, and 1 FADH 2 are produced. © 2012 Pearson Education, Inc.

55. 6.9 The citric acid cycle completes the oxidation of organic molecules, generating many NADH and FADH 2 molecules  Remember that the citric acid cycle processes two molecules of acetyl CoA for each initial glucose.  Thus, after two turns of the citric acid cycle, the overall yield per glucose molecule is –2 ATP, –6 NADH, and –2 FADH 2. © 2012 Pearson Education, Inc.

56. Figure 6.9B_s1 CoA 1 Acetyl CoA Oxaloacetate Citric Acid Cycle 2 carbons enter cycle Step Acetyl CoA stokes the furnace. 1

57. Figure 6.9B_s2 NADH NAD  HH HH CO 2 ATP ADP P CoA 321312 Acetyl CoA Oxaloacetate Citric Acid Cycle 2 carbons enter cycle Citrate leaves cycle Alpha-ketoglutarate leaves cycle Step Acetyl CoA stokes the furnace. Steps – NADH, ATP, and CO 2 are generated during redox reactions.

58. Figure 6.9B_s3 NADH NAD  NADH HH HH HH CO 2 ATP ADP P FAD FADH 2 CoA 3214534512 Acetyl CoA Oxaloacetate Citric Acid Cycle 2 carbons enter cycle Citrate leaves cycle Alpha-ketoglutarate leaves cycle Succinate Malate Step Acetyl CoA stokes the furnace. Steps – NADH, ATP, and CO 2 are generated during redox reactions. Steps – Further redox reactions generate FADH 2 and more NADH.

59. 6.10 Most ATP production occurs by oxidative phosphorylation  Oxidative phosphorylation –involves electron transport and chemiosmosis and –requires an adequate supply of oxygen. © 2012 Pearson Education, Inc.

60. 6.10 Most ATP production occurs by oxidative phosphorylation  Electrons from NADH and FADH 2 travel down the electron transport chain to O 2.  Oxygen picks up H + to form water.  Energy released by these redox reactions is used to pump H + from the mitochondrial matrix into the intermembrane space.  In chemiosmosis, the H + diffuses back across the inner membrane through ATP synthase complexes, driving the synthesis of ATP. © 2012 Pearson Education, Inc.

61. Figure 6.10 Oxidative Phosphorylation Electron Transport Chain Chemiosmosis Mito- chondrial matrix Inner mito- chondrial membrane Intermem- brane space Electron flow Protein complex of electron carriers Mobile electron carriers ATP synthase NADH NAD  2 H  FADH 2 FAD O2O2 H2OH2O ADP PATP 1 2 HH HH HH HH HH HH HH HH HH HH HH I II III IV

62. Figure 6.10_1 HH HH HH HH HH HH HH HH HH HH HH Oxidative Phosphorylation Electron Transport Chain Chemiosmosis I II III IV NADH NAD  2 H  FADH 2 FAD O2O2 H2OH2O ADP PATP 2 1 Electron flow Protein complex of electron carriers Mobile electron carriers ATP synthase

63. 6.11 CONNECTION: Interrupting cellular respiration can have both harmful and beneficial effects  Three categories of cellular poisons obstruct the process of oxidative phosphorylation. These poisons 1.block the electron transport chain (for example, rotenone, cyanide, and carbon monoxide), 2.inhibit ATP synthase (for example, the antibiotic oligomycin), or 3.make the membrane leaky to hydrogen ions (called uncouplers, examples include dinitrophenol). © 2012 Pearson Education, Inc.

64. Figure 6.11 ATP synthase NAD  NADH FADH 2 FAD HH HH HH HH HH HH HH HH 2 H  H2OH2O ADP ATP P O2O2 2 1 Rotenone Cyanide, carbon monoxide Oligomycin DNP

65. 6.11 CONNECTION: Interrupting cellular respiration can have both harmful and beneficial effects  Brown fat is –a special type of tissue associated with the generation of heat and –more abundant in hibernating mammals and newborn infants. © 2012 Pearson Education, Inc.

66. 6.11 CONNECTION: Interrupting cellular respiration can have both harmful and beneficial effects  In brown fat, –the cells are packed full of mitochondria, –the inner mitochondrial membrane contains an uncoupling protein, which allows H + to flow back down its concentration gradient without generating ATP, and –ongoing oxidation of stored fats generates additional heat. © 2012 Pearson Education, Inc.

67. 6.12 Review: Each molecule of glucose yields many molecules of ATP  Recall that the energy payoff of cellular respiration involves 1.glycolysis, 2.alteration of pyruvate, 3.the citric acid cycle, and 4.oxidative phosphorylation. © 2012 Pearson Education, Inc.

68. 6.12 Review: Each molecule of glucose yields many molecules of ATP  The total yield is about 32 ATP molecules per glucose molecule.  This is about 34% of the potential energy of a glucose molecule.  In addition, water and CO 2 are produced. © 2012 Pearson Education, Inc.

69. Figure 6.12 NADH FADH 2 NADH FADH 2 NADH or NADH Mitochondrion CYTOPLASM Electron shuttles across membrane Glycolysis Glucose 2 Pyruvate Pyruvate Oxidation 2 Acetyl CoA Citric Acid Cycle Oxidative Phosphorylation (electron transport and chemiosmosis) Maximum per glucose: by substrate-level phosphorylation by oxidative phosphorylation 2 2 2 2 62 ATP  2 about  28 ATP About ATP32ATP  2

70. FERMENTATION: ANAEROBIC HARVESTING OF ENERGY © 2012 Pearson Education, Inc.

71. 6.13 Fermentation enables cells to produce ATP without oxygen  Fermentation is a way of harvesting chemical energy that does not require oxygen. Fermentation –takes advantage of glycolysis, –produces two ATP molecules per glucose, and –reduces NAD + to NADH.  The trick of fermentation is to provide an anaerobic path for recycling NADH back to NAD +. © 2012 Pearson Education, Inc.

72. 6.13 Fermentation enables cells to produce ATP without oxygen  Your muscle cells and certain bacteria can oxidize NADH through lactic acid fermentation, in which –NADH is oxidized to NAD + and –pyruvate is reduced to lactate. © 2012 Pearson Education, Inc.

73. Animation: Fermentation Overview Right click on animation / Click play

74. 6.13 Fermentation enables cells to produce ATP without oxygen  Lactate is carried by the blood to the liver, where it is converted back to pyruvate and oxidized in the mitochondria of liver cells.  The dairy industry uses lactic acid fermentation by bacteria to make cheese and yogurt.  Other types of microbial fermentation turn –soybeans into soy sauce and –cabbage into sauerkraut. © 2012 Pearson Education, Inc.

75. Figure 6.13A 2 NAD  2 NADH 2 NAD  2 NADH 2 Lactate 2 Pyruvate Glucose 2 ADP 2 ATP 2 P Glycolysis

76. 6.13 Fermentation enables cells to produce ATP without oxygen  The baking and winemaking industries have used alcohol fermentation for thousands of years.  In this process yeasts (single-celled fungi) –oxidize NADH back to NAD + and –convert pyruvate to CO 2 and ethanol. © 2012 Pearson Education, Inc.

77. Figure 6.13B 2 NAD  2 NADH 2 NAD  2 NADH 2 Ethanol 2 Pyruvate Glucose 2 ADP 2 ATP 2 P Glycolysis 2 CO 2

78. 6.13 Fermentation enables cells to produce ATP without oxygen  Obligate anaerobes –are poisoned by oxygen, requiring anaerobic conditions, and –live in stagnant ponds and deep soils.  Facultative anaerobes –include yeasts and many bacteria, and –can make ATP by fermentation or oxidative phosphorylation. © 2012 Pearson Education, Inc.

79. Figure 6.13C_1

80. Figure 6.13C_2

81. 6.14 EVOLUTION CONNECTION: Glycolysis evolved early in the history of life on Earth  Glycolysis is the universal energy-harvesting process of life.  The role of glycolysis in fermentation and respiration dates back to –life long before oxygen was present, –when only prokaryotes inhabited the Earth, –about 3.5 billion years ago. © 2012 Pearson Education, Inc.

82. 6.14 EVOLUTION CONNECTION: Glycolysis evolved early in the history of life on Earth  The ancient history of glycolysis is supported by its –occurrence in all the domains of life and –location within the cell, using pathways that do not involve any membrane-bounded organelles. © 2012 Pearson Education, Inc.

83. CONNECTIONS BETWEEN METABOLIC PATHWAYS © 2012 Pearson Education, Inc.

84. 6.15 Cells use many kinds of organic molecules as fuel for cellular respiration  Although glucose is considered to be the primary source of sugar for respiration and fermentation, ATP is generated using –carbohydrates, –fats, and –proteins. © 2012 Pearson Education, Inc.

85. 6.15 Cells use many kinds of organic molecules as fuel for cellular respiration  Fats make excellent cellular fuel because they –contain many hydrogen atoms and thus many energy- rich electrons and –yield more than twice as much ATP per gram than a gram of carbohydrate or protein. © 2012 Pearson Education, Inc.

86. Figure 6.15 Food, such as peanuts Sugars Glycerol Fatty acidsAmino acids Amino groups Oxidative Phosphorylation Citric Acid Cycle Pyruvate Oxidation Acetyl CoA ATP Glucose G3PPyruvate Glycolysis Carbohydrates Fats Proteins

87. Figure 6.15_1 Sugars Glycerol Fatty acids Amino acids Amino groups Oxidative Phosphorylation Citric Acid Cycle Pyruvate Oxidation Acetyl CoA Glucose G3P Pyruvate Glycolysis Carbohydrates ATP Fats Proteins Food

88. 6.16 Food molecules provide raw materials for biosynthesis  Cells use intermediates from cellular respiration for the biosynthesis of other organic molecules. © 2012 Pearson Education, Inc.

89. Figure 6.16 Carbohydrates Fats Proteins Cells, tissues, organisms Amino acids Fatty acids Glycerol Sugars Amino groups Citric Acid Cycle Pyruvate Oxidation Acetyl CoA ATP needed to drive biosynthesis ATP Glucose Synthesis Pyruvate G3PGlucose

90. Figure 6.16_1 Carbohydrates Fats Proteins Cells, tissues, organisms Amino acids Fatty acids Glycerol Sugars Amino groups Citric Acid Cycle Pyruvate Oxidation Acetyl CoA ATP needed to drive biosynthesis ATP Glucose Synthesis Pyruvate G3PGlucose

91. Figure 6.16_2

92. 6.16 Food molecules provide raw materials for biosynthesis  Metabolic pathways are often regulated by feedback inhibition in which an accumulation of product suppresses the process that produces the product. © 2012 Pearson Education, Inc.

93. You should now be able to 1.Compare the processes and locations of cellular respiration and photosynthesis. 2.Explain how breathing and cellular respiration are related. 3.Provide the overall chemical equation for cellular respiration. 4.Explain how the human body uses its daily supply of ATP. © 2012 Pearson Education, Inc.

94. You should now be able to 5.Explain how the energy in a glucose molecule is released during cellular respiration. 6.Explain how redox reactions are used in cellular respiration. 7.Describe the general roles of dehydrogenase, NADH, and the electron transport chain in cellular respiration. 8.Compare the reactants, products, and energy yield of the three stages of cellular respiration. © 2012 Pearson Education, Inc.

95. You should now be able to 9.Explain how rotenone, cyanide, carbon monoxide, oligomycin, and uncouplers interrupt critical events in cellular respiration. 10.Compare the reactants, products, and energy yield of alcohol and lactic acid fermentation. 11.Distinguish between strict anaerobes and facultative anaerobes. 12.Explain how carbohydrates, fats, and proteins are used as fuel for cellular respiration. © 2012 Pearson Education, Inc.

96. Figure 6.UN01 Substrate- level phosphorylation Oxidative phosphorylation ATP NADH FADH 2 Mitochondrion Glycolysis Pyruvate Oxidation Citric Acid Cycle Oxidative Phosphorylation (electron transport and chemiosmosis) Electrons carried by NADH Glucose Pyruvate CYTOPLASM

97. Figure 6.UN02 cellular work chemiosmosis H  gradient glucose and organic fuels Cellular respiration generates has three stagesoxidizes uses produce some produces many to pull electrons down H  diffuse through ATP synthase pumps H  to create uses by a process called energy for (a) (b) (c) (d) (e) (f) (g) to

98. Figure 6.UN03 Time Color intensity a. b. c. 0.3 0.2 0.1