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': 'Trace element present in carbonic anhydrase is? \nSelect and explain. \nA. Zinc, B. Molybdenum, C. Copper, D. Magnesium', 'role': 'user'}, {'content': "Answer: A \nExplanation: Zn is an essential component of several enzymes like carbonic anhydrase, alcohol dehydrogenase, alkaline phosphatase, carboxypeptidase and superoxaide dismutase. The carbonic anhydrases (or carbonate dehydratases) form a family of enzymes that catalyze the rapid interconversion of carbon dioxide and water to bicarbonate and protons (or vice versa), a reversible reaction that occurs rather slowly in the absence of a catalyst. The active site of most carbonic anhydrases contains a zinc ion; they are therefore classified as metalloenzymes. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. (2012). Chapter 39. Acidification of the Urine & Bicarbonate Excretion. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks (Eds), Ganong's Review of Medical Physiology, 24e.", 'role': 'assistant'}]