In the TCA cycle, GTP is produced via a process referred to as substrate-level phosphorylation. Which of the following enzymes is involved in this process of formation of GTP from GDP?
A) citrate synthase
B) isocitrate dehydrogenase
C) malate dehydrogenase
D) succinate-CoA synthetase
E) succinate dehydrogenase

Question

Quizplus · Accepted Answer

Succinate-CoA synthetase catalyzes the conversion of succinyl-CoA to succinate, producing GTP from GDP in the process, which is an example of substrate-level phosphorylation in the TCA cycle.  Succinyl-CoA synthetase catalyzes the conversion of succinyl-CoA to succinate. Simultaneously, the reaction generates GTP from GDP, utilizing the high-energy bond between CoA and succinate. This formation of GTP is referred to as substrate-level phosphorylation to distinguish it from ATP production during oxidative phosphorylation.

In the TCA Cycle, GTP Is Produced Via a Process