Question

Indicate all of the following statements that are true.

Options: 1. ATP is an indirect product of the citric acid cycle

2. Acetyl CoA can increase the pool of citric acid cycle intermediates

3. Fatty acids can increase the pool of citric acid cycle intermediates

4. ADP inhibits α-ketoglutarate dehydrogenase

5. The pool of mitochondrial oxaloacetate can be increased by pyruvate

6. All enzymes of the citric acid cycle are found soluble and free in the mitochondrial matrix

Answer 1

Indicate all of the following statements that are true.

Options:

1. ATP is an indirect product of the citric acid cycle.

Incorrect: ATP is also produced directly during citric acid cycle (CAC) through substrate level phosphorylation.

2. Acetyl CoA can increase the pool of citric acid cycle intermediates

Correct: Acetyl-CoA is converted into various intermediates during CAC

3. Fatty acids can increase the pool of citric acid cycle intermediates

Correct: Fatty acids are first converted into acetyl-CoA which is further participates into CAC. Therefore, fatty acids when converted to acetyl-CoA also produce various intermediates during CAC

4. ADP inhibits α-ketoglutarate dehydrogenase.

Incorrect: ADP is an allosteric activator of the enzyme.

5. The pool of mitochondrial oxaloacetate can be increased by pyruvate

Correct: Under aerobic conditions, pyruvate is converted into acetyl-CoA. Acetyl-CoA participates in CAC and increases the pool pf mitochondrial OAA.

6. All enzymes of the citric acid cycle are found soluble and free in the mitochondrial matrix.

Incorrect: Succinate dehydrogenase is an integral protein embedded in inner mitochondrial membrane.