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Chapter 7 Table of Contents Section 1 Glycolysis and Fermentation Cellular Respiration Table of Contents Section 1 Glycolysis and Fermentation Section 2 Aerobic Respiration

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.

Fig. 9-1

Organic molecules Cellular respiration in mitochondria Fig. 9-2 Light energy ECOSYSTEM Photosynthesis in chloroplasts Organic molecules CO2 + H2O + O2 Cellular respiration in mitochondria ATP ATP powers most cellular work Heat energy

Electrons carried via NADH Electrons carried via NADH and FADH2 Fig. 9-6-3 Electrons carried via NADH Electrons carried via NADH and FADH2 Oxidative phosphorylation: electron transport and chemiosmosis Glycolysis Citric acid cycle Glucose Pyruvate Mitochondrion Cytosol ATP ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation Oxidative phosphorylation

Energy investment phase Fig. 9-8 Energy investment phase Glucose 2 ADP + 2 P 2 ATP used Energy payoff phase 4 ADP + 4 P 4 ATP formed 2 NAD+ + 4 e– + 4 H+ 2 NADH + 2 H+ 2 Pyruvate + 2 H2O Net Glucose 2 Pyruvate + 2 H2O 4 ATP formed – 2 ATP used 2 ATP 2 NAD+ + 4 e– + 4 H+ 2 NADH + 2 H+

Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA Citric acid cycle 2 Fig. 9-11 Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA Citric acid cycle 2 CO2 FADH2 3 NAD+ FAD 3 NADH + 3 H+ ADP + P i ATP

Electron transport chain 2 Chemiosmosis Fig. 9-16 H+ H+ H+ H+ Protein complex of electron carriers Cyt c V Q   ATP synthase  2 H+ + 1/2O2 H2O FADH2 FAD NADH NAD+ ADP + P ATP i (carrying electrons from food) H+ 1 Electron transport chain 2 Chemiosmosis Oxidative phosphorylation

Electron Transport Chain and Chemiosmosis, continued 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.

Citric acid cycle CYTOSOL Electron shuttles span membrane Fig. 9-17 CYTOSOL Electron shuttles span membrane MITOCHONDRION 2 NADH or 2 FADH2 2 NADH 2 NADH 6 NADH 2 FADH2 Glycolysis Oxidative phosphorylation: electron transport and chemiosmosis 2 Pyruvate 2 Acetyl CoA Citric acid cycle Glucose + 2 ATP + 2 ATP + about 32 or 34 ATP About 36 or 38 ATP Maximum per glucose:

Fig. 9-UN5 Inputs Outputs 2 ATP Glycolysis + 2 NADH Glucose 2 Pyruvate

Inputs Outputs S—CoA 2 ATP C O CH3 2 Acetyl CoA 6 NADH O C COO Fig. 9-UN6 Inputs Outputs S—CoA 2 ATP C O CH3 2 Acetyl CoA 6 NADH O C COO Citric acid cycle CH2 2 FADH2 COO 2 Oxaloacetate

INTER- MEMBRANE SPACE H+ ATP synthase ADP + P ATP MITO- CHONDRIAL Fig. 9-UN7 INTER- MEMBRANE SPACE H+ ATP synthase ADP + P ATP i MITO- CHONDRIAL MATRIX H+

Ethanol or lactate Citric acid cycle Fig. 9-19 Glucose Glycolysis CYTOSOL Pyruvate O2 present: Aerobic cellular respiration No O2 present: Fermentation MITOCHONDRION Ethanol or lactate Acetyl CoA Citric acid cycle

Cellular Respiration Versus Fermentation Section 1 Glycolysis and Fermentation Chapter 7 Cellular Respiration Versus Fermentation

Two Types of Fermentation Section 1 Glycolysis and Fermentation Chapter 7 Two Types of Fermentation

Chapter 7 Comparing Aerobic and Anaerobic Respiration Section 1 Glycolysis and Fermentation Chapter 7 Comparing Aerobic and Anaerobic Respiration

Chapter 7 Objectives Section 2 Aerobic Respiration 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.

Chapter 7 Multiple Choice Standardized Test Prep 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

Multiple Choice, continued Chapter 7 Standardized Test Prep 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

Multiple Choice, continued Chapter 7 Standardized Test Prep 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.

Multiple Choice, continued Chapter 7 Standardized Test Prep 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.

Multiple Choice, continued Chapter 7 Standardized Test Prep Multiple Choice, continued 3. Which of the following is not a product of the Krebs cycle? A. CO2 B. ATP C. FADH2 D. ethyl alcohol

Multiple Choice, continued Chapter 7 Standardized Test Prep Multiple Choice, continued 3. Which of the following is not a product of the Krebs cycle? A. CO2 B. ATP C. FADH2 D. ethyl alcohol

Multiple Choice, continued Chapter 7 Standardized Test Prep 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

Multiple Choice, continued Chapter 7 Standardized Test Prep 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

Multiple Choice, continued Chapter 7 Standardized Test Prep 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

Multiple Choice, continued Chapter 7 Standardized Test Prep 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

Multiple Choice, continued Chapter 7 Standardized Test Prep Multiple Choice, continued The illustration shows part of a biochemical pathway. Use the illustration to answer the question that follows. 6. This reaction occurs during which of the following processes? F. Krebs cycle G. acetyl CoA formation H. alcoholic fermentation J. lactic acid fermentation

Multiple Choice, continued Chapter 7 Standardized Test Prep Multiple Choice, continued The illustration shows part of a biochemical pathway. Use the illustration to answer the question that follows. 6. This reaction occurs during which of the following processes? F. Krebs cycle G. acetyl CoA formation H. alcoholic fermentation J. lactic acid fermentation

Multiple Choice, continued Chapter 7 Standardized Test Prep Multiple Choice, continued 7. glycolysis : pyruvic acid :: Krebs cycle : A. O2 B. ATP C. lactic acid D. acetyl CoA

Multiple Choice, continued Chapter 7 Standardized Test Prep Multiple Choice, continued 7. glycolysis : pyruvic acid :: Krebs cycle : A. O2 B. ATP C. lactic acid D. acetyl CoA

Multiple Choice, continued Chapter 7 Standardized Test Prep Multiple Choice, continued The illustration below shows some stages and reactants of cellular respiration. Use the illustration to answer the question that follows. 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

Multiple Choice, continued Chapter 7 Standardized Test Prep Multiple Choice, continued The illustration below shows some stages and reactants of cellular respiration. Use the illustration to answer the question that follows. 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 Short Response Standardized Test Prep 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??

Short Response, continued Chapter 7 Standardized Test Prep 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 Extended Response Standardized Test Prep 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?

Extended Response, continued Chapter 7 Standardized Test Prep 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 O2 to diffuse out of the chloroplast. In mitochondria, as O2 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.