Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Cellular Respiration
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Energy Transformations
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
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Cellular respiration – Uses O 2 and sugar (glucose) – Yields ATP
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
mitochondria Mitochondrion Intermembrane space Outer membrane Free ribosomes in the mitochondrial matrix Mitochondrial DNA Inner membrane Cristae Matrix 100 µm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Overview of cellular respiration Glycolsis GlucosePyruvate ATP Substrate-level phosphorylation Mitochondrion
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings ATP Substrate-level phosphorylation Mitochondrion Glycolsis GlucosePyruvate ATP Substrate-level phosphorylation Citric acid cycle
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
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
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
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
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