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 presence of a noncompetitive inhibitor can be implicated in which of the outcome? \nSelect and explain. \nA. Leads to both an increase in the Vmax of a reaction and an increase in the Km, B. Leads to a decrease in the observed Vmax, C. Leads to a decrease in Km and Vmax, D. Leads to an increase in Km without affecting Vmax', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In the presence of a noncompetitive inhibitor, Vmax is decreased, whereas Km is unchanged. The steady-state concentration of ES is decreased.', 'role': 'assistant'}]