How to Use This Presentation • To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show.” • To advance through the presentation, click the right-arrow key or the space bar. • From the resources slide, click on any resource to see a presentation for that resource. • From the Chapter menu screen click on any lesson to go directly to that lesson’s presentation. • You may exit the slide show at any time by pressing the Esc key. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Resources Chapter Presentation Transparencies Visual Concepts Standardized Test Prep Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Cellular Respiration Table of Contents Section 1 Glycolysis and Fermentation Section 2 Aerobic Respiration Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation 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 CO2 and water from organic compounds and O2. • 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Photosynthesis-Cellular Respiration Cycle Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Cellular Respiration Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Glycolysis Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Glycolysis Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Fermentation • If oxygen is not present, some cells can convert pyruvic acid into other compounds through additional biochemical pathways that occur in the cytosol. The combination of glycolysis and these additional pathways is fermentation. • Fermentation does not produce ATP, but it does regenerate NAD+, which allows for the continued production of ATP through glycolysis. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Cellular Respiration Versus Fermentation Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Fermentation, continued • Lactic Acid Fermentation – In lactic acid fermentation, an enzyme converts pyruvic acid into another three-carbon compound, called lactic acid. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Fermentation Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation 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 CO2. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Two Types of Fermentation Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Comparing Aerobic and Anaerobic Respiration Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 1 Glycolysis and Fermentation Efficiency of Glycolysis • 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration The Krebs Cycle • In the mitochondrial matrix, pyruvic acid produced in glycolysis reacts with coenzyme A to form acetyl CoA. Then, acetyl CoA enters the Krebs cycle. • One glucose molecule is completely broken down in two turns of the Krebs cycle. These two turns produce four CO2 molecules, two ATP molecules, and hydrogen atoms that are used to make six NADH and two FADH2 molecules. • The bulk of the energy released by the oxidation of glucose still has not been transferred to ATP. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration Krebs Cycle Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration Electron Transport Chain and Chemiosmosis • High-energy electrons in hydrogen atoms from NADH and FADH2 are passed from molecule to molecule in the electron transport chain along the inner mitochondrial membrane. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration Electron Transport Chain and Chemiosmosis, continued • Protons (hydrogen ions, H+) are also given up by NADH and FADH2. • 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration Summary of Cellular Respiration Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 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 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Standardized Test Prep Multiple Choice, continued The illustration shows 6. This reaction occurs during part of a biochemical pathway. which of the following Use the illustration to processes? answer the question that follows. F. Krebs cycle G. acetyl CoA formation H. alcoholic fermentation J. lactic acid fermentation Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Standardized Test Prep Multiple Choice, continued The illustration shows 6. This reaction occurs during part of a biochemical pathway. which of the following Use the illustration to processes? answer the question that follows. F. Krebs cycle G. acetyl CoA formation H. alcoholic fermentation J. lactic acid fermentation Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Standardized Test Prep Multiple Choice, continued 7. glycolysis : pyruvic acid :: Krebs cycle : A. O2 B. ATP C. lactic acid D. acetyl CoA Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Standardized Test Prep Multiple Choice, continued 7. glycolysis : pyruvic acid :: Krebs cycle : A. O2 B. ATP C. lactic acid D. acetyl CoA Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Standardized Test Prep Multiple Choice, continued The illustration below 8. At which of the points is shows some stages and reactants ATP, the main energy of cellular respiration. Use the currency of the cell, illustration to answer the produced? question that follows. F. 1 only G. 2 only H. 1 and 3 J. 1, 2, and 3 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Standardized Test Prep Multiple Choice, continued The illustration below 8. At which of the points is shows some stages and reactants ATP, the main energy of cellular respiration. Use the currency of the cell, illustration to answer the produced? question that follows. F. 1 only G. 2 only H. 1 and 3 J. 1, 2, and 3 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 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?? Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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 menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 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? Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. 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. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 7 Section 2 Aerobic Respiration Electron Transport Chain and Chemiosmosis Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.
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