In the body, protein buffers are very important in . defending the body against bacteria and toxins. b. maintaining acid-base balance in the body. c. accelerating chemical reactions in the body. d. maintaining and repairing body tissue.

b. maintaining acid-base balance in the body.

Explanation:

The protein buffers are the most abundant buffers in intracellular fluid and blood plasma and maintain the acid-base balance of the body. Protein hemoglobin serves as a buffer within red blood cells, and albumin is the main protein buffer in blood plasma. Proteins are polymers of amino acids.

Amino acids have at least one carboxyl group (COOH) and at least one amino group (NH2) which in turn serve as functional components of the protein buffer system. The free carboxyl group of a protein acts as an acid and releases H+ when pH rises. The released H+ ions react with any excess OH− in the solution to form water.

On the other hand, the free amino group of a protein can act as a base by combining with H+ when pH falls. In this way, protein buffers maintain the acid-base balance.

cell regulation is conducted by special proteins.