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': 'Features of competitive inhibition is/are: \nSelect and explain. \nA. Vmax increases, B. Km increases, C. Vmax decreases, D. Km decreases', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Competitive inhibition:\nThis type of inhibition occurs when the inhibitor binds reversibly to the same site that the substrate would normally occupy and, therefore, competes with the substrate for that site.\nEffect on Vmax: The effect of a competitive inhibitor is reversed by increasing the concentration of substrate. At a sufficiently high , the reaction velocity reaches the Vmax observed in the absence of inhibitor,\xa0that is, Vmax is unchanged.\nEffect on Km: A competitive inhibitor increases the apparent Km for a given substrate. This means that, in the presence of a competitive inhibitor, more substrate is needed to achieve one half Vmax.\nKey Concept:\n\nIn Competitive Inhibition\nVmax remains constant\nKm increases\n\nRef :Lippincott’s illustrated reviews for biochemistry , 7th edition.', 'role': 'assistant'}]