Becker's World of the Cell (9th Edition)
9th Edition
ISBN: 9780321934925
Author: Jeff Hardin, Gregory Paul Bertoni
Publisher: PEARSON
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Chapter 10, Problem 10.11PS
Oxidation of Cytosolic NADH. In some eukaryotic cells, the NADH generated by glycolysis in the cytosol is reoxidized by the glycerol phosphate shuttle.
(a) Write balanced reactions for the reduction of dihydroxyacetone phosphate (DHAP) to glycerol-3-phosphate (Gly-3-P) by cytosolic NADH and for the oxidation of glycerol-3-P to DHAP by the FAD-linked glycerol-3-P dehydrogenase in the inner membrane of the mitochondrion.
(b) Add the two reactions in part a to obtain a summary reaction for the transfer of electrons from cytosolic NADH to mitochondrial FAD. Calculate ΔE0′ and ΔG°′ for this reaction. Is the inward movement of electrons
(c) Write a balanced reaction for the reoxidation of FADH2 by coenzyme Q within the inner membrane, assuming that CoQ is reduced to CoQH2. Calculate ΔE0′ and ΔG°′ for this reaction. Is this transfer thermodynamically feasible under standard conditions?
(d) Write a balanced reaction for the transfer of electrons from cytosolic NADH to mitochondrial CoQ, and calculate ΔE0′ and ΔG°′ for this reaction. Is this transfer thermodynamically feasible under standard conditions?
(e) Assume that the [NADH]/[NAD+] ratio in the cytosol is 5.0 and that the [CoQH2]/[CoQ] ratio in the inner membrane is 2.0. What is ΔG′ for the reaction in part d at 25°C and pH 7.0?
(f) Is ΔG′ for the inward transfer of electrons from NADH to CoQ affected by the ratio of the reduced to the oxidized forms of the enzyme-bound FAD in the inner membrane? Why or why not?
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generation of one less FADH2 molecule.
Part C
B-oxidation dealls with only saturated fatty acids, but many fatty acids in natural lipids are unsaturated, meaning they contain one or more double bonds. Considering the fatty acid below, calculate the energy yield of its complete oxidation.
OH
Express your answer using three significant figures.
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ATP
27. Working at cross-purposes . Write a balanced equation showing the effect of simultaneous activation of glycogen phosphorylase and glycogen synthase. Include the reactions catalyzed by phosphoglucomutase and UDP-glucose pyrophosphorylase.
. Pyruvate can be processed under anaerobic conditions to ethanol (in yeast) or to lactate (in
mammals), as shown.
Explain the primary purpose of these reactions.
Describe the major biochemical features of each reaction
Chapter 10 Solutions
Becker's World of the Cell (9th Edition)
Ch. 10 - Aerobic respiration uses an external electron...Ch. 10 - Working with 3-D TEM often involves the difficult...Ch. 10 - Explain how the location and organization of the...Ch. 10 - As pyruvate is completely oxidized to CO2 in the...Ch. 10 - Why are the electron carriers in the ETS arranged...Ch. 10 - How is the chemical energy that is released as...Ch. 10 - How does the ATP synthase complex convert the...Ch. 10 - Where do the 38 ATP molecules produced during...Ch. 10 - Localization of Molecules and Functions Within the...Ch. 10 - Localization of Molecules and Functions Within the...
Ch. 10 - True or False. Indicate whether each of the...Ch. 10 - Mitochondrial Transport. For aerobic respiration,...Ch. 10 - Completing the Pathway. In each of the following...Ch. 10 - QUANTITATIVE The Calculating Cell Biologist. Use...Ch. 10 - Prob. 10.7PSCh. 10 - Regulation of Catabolism. Explain the advantage to...Ch. 10 - Lethal Synthesis. The leaves of Dichapetalum...Ch. 10 - QUANTITATIVE Oxidation of Saturated Fatty Acids....Ch. 10 - Oxidation of Cytosolic NADH. In some eukaryotic...Ch. 10 - Brown Fat and Thermogenin. Most newborn mammals,...Ch. 10 - Prob. 10.13PS
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