Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 6

The Calculating Cell Biologist. Use Table 10-2, page 272 as the basis for the calculations needed to answer the following questions.
(a)Without doing any calculations initially, predict whether isocitrate can pass electrons exergonically to NAD + under standard conditions. Why do you predict that
(b)What is the
for the oxidation of isocitrate by NAD + under standard conditions Does this calculation support the prediction you made in part a Explain your answer.
(c)Calculate the
for the oxidation of isocitrate by NAD + under standard conditions. In what way is this calculation relevant to aerobic energy metabolism
(d)Repeat parts a-c for the oxidation of lactate to pyruvate by NAD +. In what way is this calculation relevant to aerobic energy metabolism
(e)Now repeat parts a-c for the oxidation of succinate to fumarate with NAD + as the electron acceptor. You should find that the
is highly positive. What does this tell us about the likelihood that NAD + could serve as the electron acceptor for the succinate dehydrogenase reaction of the TCA cycle
(f)Finally, repeat parts a-c for the oxidation of succinate to fumarate with coenzyme Q as the electron acceptor. Why does it make sense to regard coenzyme Q as the electron acceptor when succinate dehydrogenase is shown in Figure 10-8 with FAD as the immediate electron acceptor