This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Thiamine is essential for 
Select and explain. 
A. Isocitrate dehydrogenase, B. Succinate dehydrogenase, C. Pyruvate dehydrogenase, D. Acetyl CoA synthetase
C: Pyruvate dehydrogenase
Answer: C: Pyruvate dehydrogenase 
Explanation: The  enzyme  pyruvate  dehydrogenase catalyses  (oxidative  decarboxylation)  the irreversible conversion of  pyruvate to  acetyl CoA. This reaction is dependent on thiamine pyrophosphate.