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
[{'content': 'First substrate of Kreb’s cycle is \nSelect and explain. \nA. Pyruvate, B. Glycine, C. Alanine, D. Lipoprotein', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Pyruvate, the end product of aerobic glycolysis is transported into mitochondria by specific pyruvate transporter, where it is converted to acetyl CoA by pyruvate dehydrogenase (PDH) complex.', 'role': 'assistant'}]