This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
Biotin is required for which enzyme? 
Select and explain. 
A. Acetyl CoA carboxylase, B. Propionyl CoA carboxylase, C. Methyl crotonyl CoA carboxylase, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: (D) All of the above. # Biotin is a cofactor responsible for C02 transfer in several carboxylase enzymes1. Acetyl CoA carboxylase alpha2. Acetyl CoA carboxylase beta3. Methyl clotonyl CoA carboxylase4. Propionyl CoA carboxylase5. Pyruvate carboxylase and so is important in fatty acid synthesis, branched chain aa catabolism and gluconeogenesis.