In the citric acid cycle, malate is oxidized to oxaloacetate by the enzyme malate dehydrogenase, which...

In the citric acid cycle, malate is oxidized to oxaloacetate by the enzyme malate dehydrogenase, which uses NAD+ as an electron acceptor. In cells, the ratio of [NAD+]/[NADH] is kept very high. Given the following standard reduction potentials, explain why it is so important for cells to maintain this ratio. Justify your answer with words, equations and diagrams.

oxaloacetate + 2H+ + 2e- -> malate

E°red= -0.166 V

NAD+ + H+ + 2e- > NADH

E°red= -0.320

Solutions

Expert Solution

queen_honey_blossom answered 9 months ago

Next > < Previous

Related Solutions

Consider the final reaction in the citric acid cycle, catalyzed by malate dehydrogenase: Malate + NAD+ ⇄...

Consider the final reaction in the citric acid cycle, catalyzed by malate dehydrogenase: Malate + NAD+ ⇄ oxaloacetate + NADH + H+ Equilibrium concentrations of the reaction components were measured as follows: [malate] = 5.28 mM [NAD+] = 75 uM [oxaloacetate] = 14.5 uM [NADH] = 14.5 uM pH = 8.83 a) From these data calculate the equilibrium constant, Keq, for this reaction. b) Calculate the standard free-energy change, ΔG°’, for this reaction (hint: remember that the prime means that the...

Consider the malate dehydrogenase reaction from the citric acid cycle. Given the listed concentrations, calculate the...

Consider the malate dehydrogenase reaction from the citric acid cycle. Given the listed concentrations, calculate the free energy change for this reaction at energy change for this reaction at 37.0 ∘C37.0 ∘C (310 K). Δ?∘′ΔG∘′ for the reaction is +29.7 kJ/mol+29.7 kJ/mol . Assume that the reaction occurs at pH 7. [malate]=1.53 mM [oxaloacetate]=0.240 mM [NAD+]=310 mM [NADH]=120 mM Δ? = ____ kJ⋅mol−1

Consider the malate dehydrogenase reaction from the citric acid cycle. Given the following concentrations, calculate the...

Consider the malate dehydrogenase reaction from the citric acid cycle. Given the following concentrations, calculate the free energy change for this reaction at 37.0 �C (310 K). ?G�\' for the reaction is +29.7 kJ/mol. Assume that the reaction occurs at pH 7. [malate] = 1.35 mM [oxaloacetate] = 0.150 mM [NAD ] = 310 mM [NADH] = 120 mM

Consider the malate dehydrogenase reaction from the citric acid cycle. Given the listed concentrations, calculate the...

Consider the malate dehydrogenase reaction from the citric acid cycle. Given the listed concentrations, calculate the free energy change for this reaction at energy change for this reaction at 37.0 ∘C37.0 ∘C (310 K). ΔG∘′ΔG∘′ for the reaction is +29.7 kJ/mol+29.7 kJ/mol . Assume that the reaction occurs at pH 7. [malate]=1.27 mM [oxaloacetate]=0.150 mM [NAD+]=150 mM [NADH]=6.0×101 mM ΔG:_______________kJ⋅mol−1

22. The pyruvate dehydrogenase complex provides a transition between glycolysis and the citric acid cycle. Which...

22. The pyruvate dehydrogenase complex provides a transition between glycolysis and the citric acid cycle. Which co-factors are considered stoichiometric and which are considered catalytic? 23. Which conditions exert a negative influence (reduce the activity) of pyruvate dehydrogenase? 24. What is the critical role for lipoic acid in the pyruvate dehydrogenase complex? 25. Central to the function of the citric acid cycle are two decarboxylation reactions. What are these decarboxylation reaction? 26. Your friend tells you of a celebrity touting...

3. The rate of the citric acid cycle is controlled by— A) a-ketoglutarate dehydrogenase. B) isocitrate...

3. The rate of the citric acid cycle is controlled by— A) a-ketoglutarate dehydrogenase. B) isocitrate dehydrogenase. C) citrate synthase. D) all of the above. E) none of the above

Which of these is NOT a product of the citric acid cycle?

Which of these is NOT a product of the citric acid cycle? CO2 FADH2 NADH + H+ acetyl CoA ATP

Which of these enters the citric acid cycle?

Which of these enters the citric acid cycle? G3P glucose NADH + H+ acetyl CoA pyruvate

Which CAC enzyme activity is also part of electron transport? Where is the citric acid cycle...

Which CAC enzyme activity is also part of electron transport? Where is the citric acid cycle specifically located in eukaryotic cells?

inThe citric acid cycle there are three reactions of the citric acid cycle it's self that...

inThe citric acid cycle there are three reactions of the citric acid cycle it's self that are regulated: -citrate synthase which is where ATP inhibits in in citeo -isocitrate dehydrogenase: alosterrically activated by Ca2+ and ADP also is inhibited by NADH - alpha ketoglutarate dehydrogenase which is where Ca2+ increases the rate of formation of succinyl-CoA what would happen if all three of these reactions were not present? what would happen if citrate synthase was not functioning, what would happen...

Subjects