When acetyl-CoA levels exceed the ____ supply, allosteric activation of ____ by ____ raises the oxaloacetate (OAA) levels for condensation with acetyl-CoA to form ____.

Question

Quizplus · Accepted Answer

When acetyl-CoA levels exceed the OAA supply, allosteric activation of pyruvate carboxylase by acetyl-CoA raises the OAA levels for condensation with acetyl-CoA to form citrate. This process occurs in the first step of the citric acid cycle, where pyruvate carboxylase carboxylates pyruvate to form OAA, which then condenses with acetyl-CoA to form citrate. Therefore, option D is the best answer. Option A is incorrect because citrate synthase is not allosterically activated by acetyl-CoA. Option B is incorrect because malate dehydrogenase is not involved in the acetyl-CoA condensation step, and ATP does not play a direct role in this reaction. Option C is incorrect because isocitrate does not form in the first step of the citric acid cycle, and citrate synthase is not allosterically activated by acetyl-CoA. Option E is incorrect because this statement is not in line with the question.

When Acetyl-CoA Levels Exceed the ____ Supply, Allosteric Activation of ____

When Acetyl-CoA Levels Exceed the Supply, Allosteric Activation of