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
Pyruvate dehydrogenase contains all, except - 
Select and explain. 
A. NAD, B. FAD, C. Biotin, D. CoA
C: Biotin
Answer: C: Biotin 
Explanation: PDH complex is made up of three enzymes and requires five coenzymes.The enzymes are :i) E1 : Pyruvate dehydrogenase or pyruvate decarboxylaseii) E2 : Dihydrolipoyl transacetylaseiii) E3 : Dihydrolipoyl dehydrogenase.The coenzyme required are thiamine pyrophosphate (APP), lipoic acid, FAD, NAD, and CoA.