This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Enzymes, Subject name: Biochemistry
[{'content': 'The buffering capacity of a buffer is maximum at pH equal to \nSelect and explain. \nA. 0.5 pKa, B. pKa, C. pKa+1, D. 2pKa', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The pH of a buffer is determined by the Henderson-Hasselbalch equation So, at the max buffering capacity, = . This is because a buffer reacts in the following manner--it is able to buffer against equal amounts of acid (H+) or base (OH-) added. A- + H+ - HA HA + OH- - H2O + A- Finally, we can see from the above Henderson-Hasselbalch equation that when = , pH = pKa.', 'role': 'assistant'}]