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': 'The important intermediate product of biosynthesis of fatty acid is \nSelect and explain. \nA. Cholesterol, B. Malonyl CoA, C. Acetyl CoA, D. Thioesterases', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Malonyl CoA\xa0\n\nAcetyl-CoA is the immediate substrate for fatty acid synthesis.\nHowever, acetyl-CoA needs to be converted to the activated form, which will serve as the donor of carbon units to the growing fatty acid chain.\nMalonyl-CoA is such activated form; acetyl-CoA is converted to malonyl-CoA by acetyl-CoA carboxylase.', 'role': 'assistant'}]