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 buffering capacity of a buffer is maximum when the pH is equal to: \nSelect and explain. \nA. 0.5 pKa, B. pKa, C. pKa+1, D. 2 pKa', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Buffering capacity of a buffer is most effective when the concentrations of salt and acid are equal or when pH = pKa. The effective range of a buffer is 1 pH unit higher or lower than pKa. pKa refers to the pH at which the concentration of the acid equals that of the base. Phosphate buffer is effective at a wide range because it has three pKa values. Ref: Vasudevan, Biochemistry, 3rd Edition, Page 320', 'role': 'assistant'}]