1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cellular Respiration Chapter 7 Table of Contents Section 1 Glycolysis and Fermentation Section 2 Aerobic Respiration

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Glycolysis and Fermentation Chapter 7 Objectives Identify the two major steps of cellular respiration. Describe the major events in glycolysis. Compare lactic acid fermentation with alcoholic fermentation. Calculate the efficiency of glycolysis.

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Photosynthesis-Cellular Respiration Cycle

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Photosynthesis -Cellular Respiration Cycle Section 1 Glycolysis and Fermentation

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Section 1 Cellular Respiration

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Section 1 Cellular Respiration

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Section 1 Cellular Respiration Quiz Yourself

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Section 1 Cellular Respiration

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Section 1 Cellular Respiration

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Harvesting Chemical Energy Cellular respiration is the process by which cells break down organic compounds to produce ATP. Both autotrophs and heterotrophs use cellular respiration to make CO 2 and water from organic compounds and O 2. The products of cellular respiration are the reactants in photosynthesis; conversely, the products of photosynthesis are reactants in cellular respiration. Cellular respiration can be divided into two stages: glycolysis and aerobic respiration. Section 1 Glycolysis and Fermentation

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Cellular Respiration Section 1 Glycolysis and Fermentation

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Glycolysis Cellular respiration begins with glycolysis, which takes place in the cytosol of cells. During glycolysis, one six-carbon glucose molecule is oxidized to form two three-carbon pyruvic acid molecules. A net yield of two ATP molecules is produced for every molecule of glucose that undergoes glycolysis. Section 1 Glycolysis and Fermentation

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Aerobic Respiration vs Anaerobic Fermentation Location? Pyruvic Acid Alcoholic Fermentation (makes Ethyl Alcohol) Lactic Acid Fermentation (makes Lactic Acid) Aerobic Respiration Fermentation (Anaerobic Conditions) Electron Transport Chain

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Cellular Respiration Versus Fermentation Section 1 Glycolysis and Fermentation

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Fermentation, continued Lactic Acid Fermentation –In lactic acid fermentation, an enzyme converts pyruvic acid into another three-carbon compound, called lactic acid. Section 1 Glycolysis and Fermentation

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Fermentation, continued Alcoholic Fermentation –Some plants and unicellular organisms, such as yeast, use a process called alcoholic fermentation to convert pyruvic acid into ethyl alcohol and CO 2. Section 1 Glycolysis and Fermentation

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Two Types of Fermentation Section 1 Glycolysis and Fermentation

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Fermentation, continued Through glycolysis, only about 2 percent of the energy available from the oxidation of glucose is captured as ATP. Much of the energy originally contained in glucose is still held in pyruvic acid. Glycolysis alone or as part of fermentation is not very efficient at transferring energy from glucose to ATP. Section 1 Glycolysis and Fermentation

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Objectives Relate aerobic respiration to the structure of a mitochondrion. Summarize the events of the Krebs cycle. Summarize the events of the electron transport chain and chemiosmosis. Calculate the efficiency of aerobic respiration. Contrast the roles of glycolysis and aerobic respiration in cellular respiration. Section 2 Aerobic Respiration

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Aerobic Respiration Chapter 7 Overview of Aerobic Respiration In eukaryotic cells, the processes of aerobic respiration occur in the mitochondria. Aerobic respiration only occurs if oxygen is present in the cell. The Krebs cycle occurs in the mitochondrial matrix. The electron transport chain (which is associated with chemiosmosis) is located in the inner membrane.

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Aerobic Respiration Chapter 7 Electron Transport Chain and Chemiosmosis High-energy electrons in hydrogen atoms from NADH and FADH 2 are passed from molecule to molecule in the electron transport chain along the inner mitochondrial membrane.

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Aerobic Respiration Chapter 7 Electron Transport Chain and Chemiosmosis, continued Protons (hydrogen ions, H + ) are also given up by NADH and FADH 2. As the electrons move through the electron transport chain, they lose energy. This energy is used to pump protons from the matrix into the space between the inner and outer mitochondrial membranes. The resulting high concentration of protons creates a concentration gradient of protons and a charge gradient across the inner membrane.

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Aerobic Respiration Chapter 7 Electron Transport Chain and Chemiosmosis, continued As protons move through ATP synthase and down their concentration and electrical gradients, ATP is produced. Oxygen combines with the electrons and protons to form water.

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Aerobic Respiration Chapter 7 Electron Transport Chain and Chemiosmosis, continued The Importance of Oxygen –ATP can be synthesized by chemiosmosis only if electrons continue to move along the electron transport chain. –By accepting electrons from the last molecule in the electron transport chain, oxygen allows additional electrons to pass along the chain. –As a result, ATP can continue to be made through chemiosmosis.

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Aerobic Respiration Chapter 7 Efficiency of Cellular Respiration Cellular respiration can produce up to 38 ATP molecules from the oxidation of a single molecule of glucose. Most eukaryotic cells produce about 36 ATP molecules per molecule of glucose. Thus, cellular respiration is nearly 20 times more efficient than glycolysis alone.

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Aerobic Respiration Chapter 7 A Summary of Cellular Respiration Another Role of Cellular Respiration –Providingn cells with ATP is not the only important function of cellular respiration. –Molecules formed at different steps in glycolysis and the Krebs cycle are often used by cells to make compounds that are missing in food.

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Aerobic Respiration Chapter 7 Electron Transport Chain and Chemiosmosis

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Section 1 Cellular Respiration

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 7 Summary of Cellular Respiration Section 2 Aerobic Respiration

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice 1. Which of the following must pyruvic acid be converted into before the Krebs cycle can proceed? A. NADH B. glucose C. citric acid D. acetyl CoA Standardized Test Prep Chapter 7

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 1. Which of the following must pyruvic acid be converted into before the Krebs cycle can proceed? A. NADH B. glucose C. citric acid D. acetyl CoA Standardized Test Prep Chapter 7

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 2. Which of the following occurs in lactic acid fermentation? F. Oxygen is consumed. G. Lactic acid is converted into pyruvic acid. H. NAD + is regenerated for use in glycolysis. J. Electrons pass through the electron transport chain. Standardized Test Prep Chapter 7

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 2. Which of the following occurs in lactic acid fermentation? F. Oxygen is consumed. G. Lactic acid is converted into pyruvic acid. H. NAD + is regenerated for use in glycolysis. J. Electrons pass through the electron transport chain. Standardized Test Prep Chapter 7

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 3. Which of the following is not a product of the Krebs cycle? A. CO 2 B. ATP C. FADH 2 D. ethyl alcohol Standardized Test Prep Chapter 7

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 3. Which of the following is not a product of the Krebs cycle? A. CO 2 B. ATP C. FADH 2 D. ethyl alcohol Standardized Test Prep Chapter 7

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 4. In which way is cellular respiration similar to photosynthesis? F. They both make G3P. G. They both involve ATP. H. They both involve chemiosmosis. J. all of the above Standardized Test Prep Chapter 7

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 4. In which way is cellular respiration similar to photosynthesis? F. They both make G3P. G. They both involve ATP. H. They both involve chemiosmosis. J. all of the above Standardized Test Prep Chapter 7

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 5. ATP is synthesized in chemiosmosis when which of the following moves across the inner mitochondrial membrane? A. NADH B. oxygen C. protons D. citric acid Standardized Test Prep Chapter 7

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 5. ATP is synthesized in chemiosmosis when which of the following moves across the inner mitochondrial membrane? A. NADH B. oxygen C. protons D. citric acid Standardized Test Prep Chapter 7

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 6. This reaction occurs during which of the following processes? F. Krebs cycle G. acetyl CoA formation H. alcoholic fermentation J. lactic acid fermentation Chapter 7 The illustration shows part of a biochemical pathway. Use the illustration to answer the question that follows. Standardized Test Prep

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 6. This reaction occurs during which of the following processes? F. Krebs cycle G. acetyl CoA formation H. alcoholic fermentation J. lactic acid fermentation Chapter 7 The illustration shows part of a biochemical pathway. Use the illustration to answer the question that follows. Standardized Test Prep

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 7. glycolysis : pyruvic acid :: Krebs cycle : A. O 2 B. ATP C. lactic acid D. acetyl CoA Chapter 7 Standardized Test Prep

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 7. glycolysis : pyruvic acid :: Krebs cycle : A. O 2 B. ATP C. lactic acid D. acetyl CoA Chapter 7 Standardized Test Prep

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 8. At which of the points is ATP, the main energy currency of the cell, produced? F. 1 only G. 2 only H. 1 and 3 J. 1, 2, and 3 Chapter 7 The illustration below shows some stages and reactants of cellular respiration. Use the illustration to answer the question that follows. Standardized Test Prep

45. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 8. At which of the points is ATP, the main energy currency of the cell, produced? F. 1 only G. 2 only H. 1 and 3 J. 1, 2, and 3 Chapter 7 The illustration below shows some stages and reactants of cellular respiration. Use the illustration to answer the question that follows. Standardized Test Prep

46. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response The inner membrane of a mitochondrion is folded; these folds are called cristae. How might cellular respiration be different if the inner mitochondrial membrane were not folded? Chapter 7 Standardized Test Prep

47. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued The inner membrane of a mitochondrion is folded; these folds are called cristae. How might cellular respiration be different if the inner mitochondrial membrane were not folded? Answer: The cristae increase the surface area of the inner wall of the mitochondria, which allows more electron transport chain pathways and ATP synthase. Thus, the rate of cellular respiration is increased. Chapter 7 Standardized Test Prep

48. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response Oxygen is produced during the reactions of photosynthesis, and it is used in the reactions of cellular respiration. Part A How does oxygen get into or out of chloroplasts and mitochondria? Part B What are the roles of oxygen in the processes of photosynthesis and cellular respiration, and how are the roles similar? Chapter 7 Standardized Test Prep

49. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response, continued Answer: Part A Oxygen builds up inside chloroplasts as they produce oxygen, forming a concentration gradient—high oxygen concentration inside and low concentration outside. This causes O 2 to diffuse out of the chloroplast. In mitochondria, as O 2 is used up, a favorable gradient for the inward diffusion of oxygen occurs. Part B In photosynthesis, oxygen is formed when water is split during the light reactions. This byproduct of photosynthesis is released by cells and becomes available for aerobic respiration. In aerobic respiration, oxygen is the final electron acceptor at the end of electron transport. When oxygen accepts these electrons (and protons), water is formed. Hence, water supplies oxygen for photosynthesis, and oxygen is used to form water in aerobic respiration. Chapter 7 Standardized Test Prep