Which enzyme is responsible for the conversion of succinyl CoA to succinate?

The enzyme responsible for the conversion of succinyl CoA to succinate is succinyl CoA synthetase. This enzyme plays a crucial role in the citric acid cycle by catalyzing a substrate-level phosphorylation reaction. During this process, succinyl CoA, which contains a high-energy thioester bond, is converted to succinate, releasing CoA and generating GTP or ATP, depending on the specific organism or tissue type. The energy released during this reaction is harnessed to form a nucleotide triphosphate, thereby contributing to the energy yield of the cycle.

In the context of the citric acid cycle, this reaction is significant as it represents one of the rare instances where energy is directly converted into a usable form (GTP or ATP) rather than being captured in the form of NADH or FADH2, as seen in other steps of the cycle. Succinyl CoA synthetase's activity illustrates a key reaction that not only facilitates the transformation of metabolites but also links metabolism to energy production in cells.