This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Link reaction, Subject name: Biochemistry
[{'content': 'Pyruvate Dehydrogenase complex has all enzyme components EXCEPT: \nSelect and explain. \nA. Pyruvate Dehydrogenase, B. Dihydrolipoyl Transacetylase, C. Dihydrolipoyl Dehydrogenase, D. Pyruvate Decarboxylase', 'role': 'user'}, {'content': 'Answer: D \nExplanation: PDH complex has 3 enzyme components: 1. E1: Pyruvate Dehydrogenase 2. E2: Dihydrolipoyl Transacetylase 3. E3: Dihydrolipoyl Dehydrogenase REGULATION OF PDH End Product Inhibition Covalent Modification Acetyl CoA (in fasting) NADH Active in dephosphorylated state Done by Insulin', 'role': 'assistant'}]