Exam 14: Citric Acid Cycle and Glyoxylate Cycle

The glyoxylate cycle reaction catalyzed by isocitrate lyase is a reversible aldol condensation.As it is written below,the reaction is an aldol cleavage.Propose a mechanism for this reaction using the acid and base supplied by the enzyme.

Which of the following citric acid cycle enzymes is bypassed in the glyoxylate cycle?

What role does the coenzyme A portion of acetyl-CoA play in the reaction catalyzed by citrate synthase?

Draw the enzyme-bound intermediate of the following reaction clearly showing proper stereochemistry:

Which oxidation reaction requires the coenzyme FAD because it involves oxidation of a carbon-carbon single bond to a double bond?

Which of the following is an enzyme-bound intermediate in the reaction catalyzed by succinyl-CoA synthetase?

Which of the following coenzymes is required for the decarboxylation of pyruvate by the pyruvate dehydrogenase complex?

The complete oxidation of the acetyl group that enters the citric acid cycle yields _____ electrons from the methyl carbon and ____ electrons from the carbonyl carbon.

Which of the following is an inhibitor of citrate synthase,isocitrate dehydrogenase,and $\alpha$ -ketoglutarate dehydrogenase?

Which of the following molecules is correctly paired with the enzyme that can convert it to oxaloacetate to replenish the citric acid cycle when other intermediates are removed?

For each molecule of acetyl-CoA that enters the citric acid cycle,which of the following best represents the net products of the cycle?

Which of the following correctly lists the products of the pyruvate dehydrogenase complex in the correct order of release?

Which of the following best explains why thioesters have a greater free energy of hydrolysis than ordinary esters?

Which of the following enzymes of the pyruvate dehydrogenase complex is responsible for the oxidation of the hydroxyethyl group from pyruvate decarboxylation to an acetyl group?

In the citric acid cycle,acetyl-CoA reacts with ________ to produce _________.

__________ activates __________,thereby inhibiting pyruvate dehydrogenase.

The oxidation reactions that convert pyruvate to CO₂ are specifically catalyzed by ______ enzymes.

Which of the following is an equilibrium-controlled reaction of the citric acid cycle?

Arsenic poisoning by either arsenite or organic arsenical agents work by binding to dithiol compounds such as _________ meaning that in addition to inactivation of pyruvate dehydrogenase,the citric acid cycle enzyme _________ would be inactivated.

Which of the following reactions is commonly used to replenish intermediates of the citric acid cycle?