Buffer systems in the body maintain proper pH balance in order for life processes to proceed. Proteins found in the blood plasma are often used as buffers. What makes a protein able to function as a buffer?

A buffer helps resist changes in pH by accepting excess hydrogen ions (protons) or releasing protons when they are needed. Proteins can do this because some of their chemical groups can gain or lose protons. Therefore, the correct choice is “The protein must be capable of both accepting and releasing protons.”

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