How do Organisms Supply Themselves with Energy
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 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 Energy flow and chemical recycling in ecosystems
Respiration C 6 H 12 O O 2 6 CO H 2 O Photosynthesis 6 CO H 2 O C 6 H 12 O O 2 CO 2 + H 2 O C(H 2 O) + 6 O 2
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings H / 2 O 2 2 H 1 / 2 O 2 (from food via NADH) 2 H e – 2 H + 2 e – H2OH2O 1 / 2 O 2 Controlled release of energy for synthesis of ATP ATP Electron transport chain Free energy, G (b) Cellular respiration (a) Uncontrolled reaction Free energy, G H2OH2O Explosive release of heat and light energy + Figure 9.5 An introduction to electron transport chains
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 9.6 An overview of cellular respiration Glycolsis GlucosePyruvate ATP Substrate-level phosphorylation Mitochondrion
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 9.6 An overview of cellular respiration ATP Substrate-level phosphorylation Mitochondrion Glycolsis GlucosePyruvate ATP Substrate-level phosphorylation Citric acid cycle
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 9.6 An overview of cellular respiration 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 Figure 9.13 Free-energy change during electron transport Glycolysis Citirc acid cycle Oxidative phosphorylation ATP H2OH2O O2O2 NADH FADH 2 FMN FeS O FAD Cyt b Cyt c 1 Cyt c Cyt a Cyt a 3 2 H 2 I II III IV Multiprotein complexes Free energy (G) relative to O 2 (kcl/mol)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 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 Pyruvate as a key juncture in catabolism
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Amino acids Sugars Glycerol Fatty acids Glycolysis Glucose Glyceraldehyde-3- P Pyruvate Acetyl CoA NH 3 Citric acid cycle Oxidative phosphorylation Fats Proteins Carbohydrates Figure 9.19 The catabolism of various molecules from food
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Glucose Glycolysis Fructose-6-phosphate Phosphofructokinase Fructose-1,6-bisphosphate Inhibits Pyruvate ATP Acetyl CoA Citric acid cycle Citrate Oxidative phosphorylation Stimulates AMP + – – Figure 9.20 The control of cellular respiration