~~ ~~ Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display GLUCOSE Pentose phosphate pathway Starts the oxidation of glucose Glycolysis Oxidizes glucose to pyruvate Reducing power ATP by substrate-level phosphorylation Fermentation Reduces pyruvate or a derivative Biosynthesis Transition step Acetyl- CoA Acetyl- CoA Respiration Uses the electron transport chain to convert reducing power to proton motive force ATP by oxidative phosphorylation ATP by substrate-level phosphorylation Reducing power TCA cycle Incorporates an acetyl group and releases CO 2 (TCA cycles twice) CO 2 3a X 2 CO 2 3b Yields Reducing power Reducing power ~~ Acids, alcohols, and gases Pyruvate

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Pentose phosphate pathway Ribose 5-phosphate Erythrose 5-phosphate Nucleotides amino acids (histidine) Amino acids (phenylalanine, tryptophan, tyrosine) Lipids (glycerol component) Amino acids (cysteine, glycine, serine) Amino acids (phenylalanine, tryptophan, tyrosine) Amino acids (aspartate, asparagine, isoleucine, lysine, methionine, threonine) TCA cycle Amino acids (arginine, glutamate, glutamine, proline) Lipids (fatty acids) Amino acids (alanine, leucine, valine) Peptidoglycan Lipopolysaccharide (polysaccharide) Glucose 6-phosphate Fructose 6-phosphate Dihydroxyacetone phosphate 3-phosphoglycerate Phosphoenolpyruvate Pyruvate Acetyl-CoA Pyruvate Oxaloacetate  - ketoglutarate Glycolysis X 2

The Central Metabolic Pathways ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~ + + x2 PP P PPP P PP b ~~ ~~ ~ GLUCOSE Yields Fermentation Reduces pyruvate or a derivative Pyruvate Reducing power Yields Biosynthesis Transition step 3a Yields Reducing power CO 2 TCA cycle Incorporates an acetyl group and releases CO2 (TCA cycles twice) ATP by substrate-level phosphorylation Reducing power Respiration Uses the electron transport Chain to convert reducing power to proton motive force Yields ATP by oxidative phosphorylation ~ H2OH2O ATP is expended to add a phosphate group. A chemical rearrangement occurs. ATP is expended to add a phosphate group. The 6-carbon molecule is split into two 3-carbon molecules. A chemical rearrangement of one of the molecules occurs. The addition of a phosphate group is coupled to a redox reaction, generating NADH and a high-energy phosphate bond. ATP is produced by substrate-level phosphorylation. A chemical rearrangement occurs. Water is removed, causing the phosphate bond to become high-energy. ATP is produced by substrate-level phosphorylation. Pyruvate ATP ADP Phospho- enolpyruvate 2-phospho- glycerate 3-phospho- glycerate ATP ADP 1,3-bisphospho- glycerate Glyceraldehyde 3-phosphate Dihydroxyacetone phosphate Fructose 1,6-bisphosphate ADP ATP Fructose 6-phosphate Glucose 6-phosphate 10 H2OH2O NADH + H + NAD + Glucose ATP ADP NADH + H + NAD + Pentose phosphate pathway Starts the oxidation of glucose Glycolysis Oxidizes glucose to pyruvate Reducing power ATP by substrate-level phosphorylation Acids, alcohols, and gases Yields ~ ~ Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glycolysis –Converts 1 glucose to 2 pyruvates; yields net 2 ATP, 2 NADH –Investment phase: 2 phosphate groups added Glucose split to two 3-carbon molecules –Pay-off phase: 3-carbon molecules converted to pyruvate Generates 4 ATP, 2 NADH total

The Central Metabolic Pathways Transition Step –CO 2 is removed from pyruvate –Electrons reduce NAD + to NADH + H + –2-carbon acetyl group joined to coenzyme A to form acetyl-CoA –Takes place in mitochondria in eukaryotes Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ~~ ~ + PiPi H2OH2O A redox reaction generates NADH. Water is added. A redox reaction generates FADH 2- The energy released during CoA removal is harvested to produce ATP. ADP ATP CoA A redox reaction generates NADH, CO 2 is removed, and coenzyme A is added. A redox reaction generates NADH and CO 2 is removed. A chemical rearrangement occurs. The acetyl group is transferred to oxaloacetate to start a new round of the cycle. Transition step: CO 2 is removed, a redox reaction generates NADH, and coenzyme A is added. NADH + H + Acetyl-CoA CoA NADH + H + Oxaloacetate NAD + Malate Fumarate FADH 2 FAD Succinate Succinyl-CoA CoA CO 2 NAD +  -ketoglutarate Isocitrate Citrate CoA NAD + CO 2 Pyruvate NAD + CO 2 NADH + H x ~~ ~~ ~~ GLUCOSE Respiration Uses the electron transport chain to convert reducing power to proton motive force ATP by oxidative phosphorylation Yields ATP by substrate-level phosphorylation Reducing power Yields CO 2 Pyruvate 3aTransition step Yields Reducing power Acetyl- CoA Acetyl- CoA Biosynthesis Yields Reducing power Pentose phosphate pathway Starts the oxidation of glucose Glycolysis Oxidizes glucose to pyruvate Yields Reducing power ATP by substrate-level phosphorylation Acids, alcohols, and gases CO 2 Fermentation Reduces pyruvate or a derivative TCA cycle Incorporates an acetyl group and releases CO 2 (TCA cycles twice) 3b

The Electron Transport Chain of Mitochondria Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Pentose phosphate pathway Starts the oxidation of glucose GLUCOSE Glycolysis Oxidizes glucose to pyruvate Yields Reducing power ATP by substrate-level phosphorylation Fermentation Reduces pyruvate or a derivative Acids, alcohols, and gases Pyruvate Reducing power Yields Biosynthesis Transition step3a Yields Reducing power CO 2 Acetyl- CoA Acetyl- CoA CO 2 TCA cycle Incorporates an acetyl group and releases CO 2 (TCA cycles twice) Yields ATP by substrate-level phosphorylation Reducing power Respiration Uses the electron transport chain to convert reducing power to proton motive force Yields ATP by oxidative phosphorylation x 2 3b + PPP ~~ PPP H+H+ 10H+H+ +3 PiPi H2OH2O O2O2 2 e–e– Eukaryotic cell Inner mitochondrial membrane Electron Transport Chain Complex I Ubiquinone Complex III NADH Complex II 3 ADP 3 ATP Mitochondrial matrix Intermembrane space Use of Proton Motive Force ATP synthase (ATP synthesis) Complex IV Proton motive force is used to drive: Terminal electron acceptor Cytochrome c NAD + H+H+ H+H+ H+H+ H+H+ 1/21/2 Path of electrons 2

The Electron Transport Chain—Generating Proton Motive Force Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. veforce rive: + H+H+ H+H+ Terminal electron acceptor – O2O2 Prokaryotic cell Cytoplasmic membrane Electron Transport Chain NADH dehydrogenase H + (0 or 4) Uses of Proton Motive Force Rotation of a flagella Outside of cytoplasmic membrane Transported molecule NADH Cytoplasm 3 ADP 3 ATP + 3 P i NAD + H+H+ Succinate dehydrogenase Path of electrons Ubiquinone Active transport (one mechanism) ATP synthase (ATP synthesis) Ubiquinol oxidase H + (2 or 4) 10 H + H2OH2O 2 H + Proton motive force is used to drive: 2 e – 1/21/2

Fig H H O H3CH3C C O H H3CH3C C H Pyruvate Acetaldehyde Ethanol H3CH3CC C O O–O– OH NAD + Lactate CO 2 NADH + NAD + H+H+ (a) Lactic acid fermentation Pyruvate H3CH3C C OO CO–O– O OH O–O– H3CH3C CC NADH H+H+ + + x 2 PPP PP P PPP b ~~ ~~ ~ ~ Pentose phosphate pathway Starts the oxidation of glucose Glycolysis Oxidizes glucose to pyruvate Yields Reducing power ATP by substrate-level phosphorylation Fermentation Reduces pyruvate or a derivative Acids, alcohols, and gases Pyruvate Reducing power Yields Biosynthesis Transition step 3a Yields Reducing power CO 2 Acetyl- CoA Acetyl- CoA CO 2 TCA cycle Incorporates an acetyl group and releases CO 2 (TCA cycles twice) Yields ATP by substrate-level phosphorylation Reducing power Respiration Uses the electron transport chain to convert reducing power to proton motive force Yields ATP by oxidative phosphorylation (b) Ethanol fermentation Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. + GLUCOSE