Which of the following compounds is involved in the conversion of succinyl-CoA to succinate?

The conversion of succinyl-CoA to succinate is a key step in the citric acid cycle, specifically during the process known as substrate-level phosphorylation. In this reaction, succinyl-CoA is transformed into succinate with the concomitant phosphorylation of GDP to GTP. This is significant because GTP can be readily converted to ATP, thus representing a direct means of energy production.

During this reaction, succinyl-CoA donates its CoA group and subsequently loses a high-energy thioester bond, leading to the formation of succinate. The energy released from the breakdown of succinyl-CoA is captured by the phosphorylation of GDP to GTP. This coupling of reaction is facilitated by the enzyme succinyl-CoA synthetase (also known as succinate thiokinase), which plays a crucial role in energy metabolism.

Other options like NAD+, TPP, and FADH2 are not directly involved in this particular conversion. NAD+ is primarily involved in oxidation-reduction reactions, specifically in the oxidative steps of the citric acid cycle, while TPP (thiamine pyrophosphate) serves as a coenzyme in various decarboxylation reactions. FADH2, on the other