Problem 1
The bottom line. What is the net equation of the citric acid cycle?
Problem 2
A hoax, perhaps? The citric acid cycle is part of aerobic respiration, but no \(\mathrm{O}_{2}\) is required for the cycle. Explain this paradox.
Problem 3
Thing 1 and Thing \(2 .\) The citric acid cycle can be thought of as taking place in two stages. What are the two stages?
Problem 4
Like Jack and Jill. Match each enzyme with its description. (a) Pyruvate dehydrogenase complex__________ (b) Citrate synthase__________ (c) Aconitase__________ (d) Isocitrate dehydrogenase__________ (e) \(\alpha\) -Ketoglutarate dehydrogenase__________ (f) Succinyl CoA synthetase__________ (g) Succinate dehydrogenase__________ (h) Fumarase__________ (i) Malate dehydrogenase__________ (j) Pyruvate carboxylase__________ 1\. Catalyzes the formation of isocitrate 2\. Synthesizes succinyl CoA 3\. Generates malate 4\. Generates ATP 5\. Converts pyruvate into acetyl CoA 6\. Converts pyruvate into oxaloacetate 7\. Condenses oxaloacetate and acetyl CoA 8\. Catalyzes the formation of oxaloacetate 9\. Synthesizes fumarate 10\. Catalyzes the formation of \(\alpha\) -ketoglutarate
Problem 5
One from two. The synthesis of citrate from acetyl CoA and oxaloacetate is a biosynthetic reaction. What is the energy source that drives the formation of citrate?
Problem 6
A penny saved.... How is the wasteful hydrolysis of acetyl CoA prevented by citrate synthase?
Problem 9
Acting catalytically. The citric acid cycle itself, which is composed of enzymatically catalyzed steps, can be thought of as essentially a supramolecular enzyme. Explain.
Problem 10
Seven o'clock roadblock. Malonate is a competitive inhibitor of succinate dehydrogenase. How will the concentrations of citric acid cycle intermediates change immediately after the addition of malonate? Why is malonate not a substrate for succinate dehydrogenase? (EQUATION CAN'T COPY)
Problem 11
One of a kind. How is succinate dehydrogenase unique compared with the other enzymes in the citric acid cycle?
Problem 12
Phosphate requirement. What step in the citric acid cycle requires a molecule of inorganic phosphate?
