1. End Show 9-2 The Krebs Cycle and Electron Transport Slide 1 of 37 Copyright Pearson Prentice Hall 9-2 The Krebs Cycle and Electron Transport 77. What is required for the final steps of cellular respiration (CR)? Oxygen (O2) is required, so CR’s reactions are said to be aerobic. 78. What happens during the Krebs Cycle (KC)? In the presence of O2, pyruvic acid produced in glycolysis passes to the second stage of cellular respiration, the KC.

2. End Show Slide 2 of 37 9-2 The Krebs Cycle and Electron Transport Copyright Pearson Prentice Hall The Krebs Cycle 79. What happens during the KC? During the KC, pyruvic acid is broken down into CO2 in a series of energy-extracting reactions. 80. What are characteristics of the KC? it begins when pyruvic acid produced by glycolysis enters the mitochondrion. 1 carbon molecule is removed, forming CO2, and electrons are removed. 1 molecule of ATP is generated.

3. End Show Slide 3 of 37 Copyright Pearson Prentice Hall When the pyruvic acid from glycolysis enters the _______, and in the presence of O2, the _____ ______ begins. How much ATP is produced during the Krebs Cycle?

4. End Show 9-2 The Krebs Cycle and Electron Transport Slide 4 of 37 Copyright Pearson Prentice Hall Electron Transport 81. How are high-energy electrons used by the electron transport chain (ETC)? The ETC uses the high-energy electrons from the Krebs cycle to convert ADP into ATP. 82. How much ATP does each pair of electrons in the ETC create? On average, each pair of high-energy electrons that moves down the ETC provides enough energy to produce 3 molecules of ATP from ADP.

5. End Show 9-2 The Krebs Cycle and Electron Transport Slide 5 of 37 Copyright Pearson Prentice Hall The Totals 83. How much ATP is generated in all the CR cycles? glycolysis produces just 2 ATP molecules per molecule of glucose. the complete breakdown of glucose through cellular respiration, including glycolysis, results in the production of 36 molecules of ATP.

6. End Show 9-2 The Krebs Cycle and Electron Transport Slide 6 of 37 Copyright Pearson Prentice Hall The Totals

7. End Show 9-2 The Krebs Cycle and Electron Transport Slide 7 of 37 Copyright Pearson Prentice Hall Comparing Photosynthesis and Cellular Respiration 84. How are CR and photosynthesis (PS) related? The energy flows in PS and CR take place in opposite directions. (Photosynthesis) (Cellular Respiration)

8. End Show 9-2 The Krebs Cycle and Electron Transport Slide 8 of 37 Copyright Pearson Prentice Hall Comparing Photosynthesis and Cellular Respiration 85. On a global level, how are PS and CR related? They are opposites: PS removes CO2 from the atmosphere and CR puts it back. PS releases O2into the atmosphere and CR uses that O2to release energy from food.

9. End Show Slide 9 of 37 Copyright Pearson Prentice Hall _____ _____ ______ provide the energy necessary for the conversion of ADP to ATP. How many ATPs are produced by the three stages of CR? PS removes _____ & _____ from the atmosphere, while CR removes ______ from it.

10. End Show Slide 10 of 37 Copyright Pearson Prentice Hall 9-2 The Krebs cycle breaks pyruvic acid down into a.oxygen. b.NADH. c.carbon dioxide. d.alcohol.

11. End Show Slide 11 of 37 Copyright Pearson Prentice Hall 9-2 What role does the Krebs cycle play in the cell? a.It breaks down glucose and releases its stored energy. b.It releases energy from molecules formed during glycolysis. c.It combines carbon dioxide and water into high-energy molecules. d.It breaks down ATP and NADH, releasing stored energy.

12. End Show Slide 12 of 37 Copyright Pearson Prentice Hall 9-2 Which statement correctly describes photosynthesis and cellular respiration? a.Photosynthesis releases energy, while cellular respiration stores energy. b.Photosynthesis and cellular respiration use the same raw materials. c.Cellular respiration releases energy, while photosynthesis stores energy. d.Cellular respiration and photosynthesis produce the same products.