Thiamine pyrophosphate functions as a coenzyme in which reactions in the citrate cycle?
A) pyruvate dehydrogenase and succinate dehydrogenase
B) pyruvate dehydrogenase and -ketoglutarate dehydrogenase
C) malate dehydrogenase and succinate dehydrogenase
D) malate dehydrogenase and -ketoglutarate dehydrogenase

Question

Thiamine pyrophosphate functions as a coenzyme in which reactions in the citrate cycle?
A) pyruvate dehydrogenase and succinate dehydrogenase 
B) pyruvate dehydrogenase and -ketoglutarate dehydrogenase 
C) malate dehydrogenase and succinate dehydrogenase 
D) malate dehydrogenase and -ketoglutarate dehydrogenase

Quizplus · Accepted Answer

Thiamine pyrophosphate functions as a coenzyme in the pyruvate dehydrogenase and α-ketoglutarate dehydrogenase reactions in the citrate cycle, which are involved in the conversion of pyruvate to acetyl-CoA and α-ketoglutarate to succinyl-CoA. Therefore, the best choice is B.

Thiamine Pyrophosphate Functions as a Coenzyme in Which Reactions in the Citrate