This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Enzyme Kinetics, Subject name: Biochemistry
[{'content': 'Km of an enzyme is: \nSelect and explain. \nA. Dissociation constant, B. The normal physiological substrate concentration, C. The substrate concentration that produces half maximum velocity, D. Numerically identical for all isozymes that catalyze a given reaction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. The substrate concentration that produces half maximum velocityThe substrate concentration that produces half maximal velocity (v termed the K value or Michaelis constant)', 'role': 'assistant'}]