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': 'Which of the following enzymes is involved in the process of both cholesterol and ketone bodies metabolism \nSelect and explain. \nA. HMG CoA reductase, B. HMG CoA synthase, C. HMG CoA lyase, D. Thiokinase', 'role': 'user'}, {'content': 'Answer: B \nExplanation: HMG CoA synthase\xa0\n\nThe first two reactions in the cholesterol synthetic pathway and ketone bodies synthesis are the same\n\n\nFirst, two acetyl CoA molecules condense to form acetoacetyl CoA in the presence of thiolase.\nNext, the third molecule of acetyl-CoA is added to produce HMG-CoA, a reaction catalyzed by enzyme HMG-CoA synthase.\n\n\nLiver parenchymal cells contain two isoenzymes of HMG-CoA synthase:-\n\n(1) Cytosolic enzyme\xa0→ For cholesterol synthesis\nMitochondrial enzyme\xa0→ For ketone body synthesis', 'role': 'assistant'}]