1. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Cellular Respiration

2. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Energy Transformations

3. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings E Transformations  Thermodynamics E flows into ecosystem as sunlight Light energy ECOSYSTEM CO 2 + H 2 O Photosynthesis in chloroplasts Cellular respiration in mitochondria Organic molecules + O 2 ATP powers most cellular work Heat energy Figure 9.2

4. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Cellular respiration – Uses O 2 and sugar (glucose) – Yields ATP

5. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

6. mitochondria Mitochondrion Intermembrane space Outer membrane Free ribosomes in the mitochondrial matrix Mitochondrial DNA Inner membrane Cristae Matrix 100 µm

7. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Overview of cellular respiration Glycolsis GlucosePyruvate ATP Substrate-level phosphorylation Mitochondrion

8. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings ATP Substrate-level phosphorylation Mitochondrion Glycolsis GlucosePyruvate ATP Substrate-level phosphorylation Citric acid cycle

9. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Electrons carried via NADH Glycolsis GlucosePyruvate ATP Substrate-level phosphorylation Electrons carried via NADH and FADH 2 Citric acid cycle Oxidative phosphorylation: electron transport and chemiosmosis ATP Substrate-level phosphorylation Oxidative phosphorylation Mitochondrion

10. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Overview of cellular respiration Figure 9.6 Electrons carried via NADH Glycolsis Glucose Pyruvate ATP Substrate-level phosphorylation Electrons carried via NADH and FADH 2 Citric acid cycle Oxidative phosphorylation: electron transport and chemiosmosis ATP Substrate-level phosphorylation Oxidative phosphorylation Mitochondrion Cytosol

11. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 3 main processes in metabolism Electron shuttles span membrane CYTOSOL 2 NADH 2 FADH 2 2 NADH 6 NADH 2 FADH 2 2 NADH Glycolysis Glucose 2 Pyruvate 2 Acetyl CoA Citric acid cycle Oxidative phosphorylation: electron transport and chemiosmosis MITOCHONDRION by substrate-level phosphorylation by substrate-level phosphorylation by oxidative phosphorylation, depending on which shuttle transports electrons from NADH in cytosol Maximum per glucose: About 36 or 38 ATP + 2 ATP + about 32 or 34 ATP or Figure 9.16

12. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 2 possible pathways, with and without oxygen Glucose CYTOSOL Pyruvate No O 2 present Fermentation O 2 present Cellular respiration Ethanol or lactate Acetyl CoA MITOCHONDRION Citric acid cycle Figure 9.18

13. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Evolutionary Significance of Glycolysis Glycolysis occurs in nearly all organisms Probably evolved before O 2 in the atmosphere