Acid-base buffer system

The acid-base buffer system refers to chemical equilibria in biological and chemical solutions that resist significant pH changes upon addition of small amounts of acid or base, typically consisting of a weak acid and its conjugate base or a weak base and its conjugate acid. In human physiology, key systems include the bicarbonate-carbonic acid buffer (HCO3-/H2CO3), which maintains blood pH around 7.4 through equilibrium with CO2 and H2O, regulated by lungs and kidneys; the phosphate buffer (H2PO4-/HPO4 2-), active intracellularly and in urine; and protein buffers like hemoglobin and albumin that bind or release H+ ions. These systems ensure optimal conditions for enzymatic activity, oxygen transport, and cellular function, preventing disruptions that lead to acidosis or alkalosis. While not a specific molecular entity like a receptor or enzyme, buffer systems are fundamental to homeostasis but are not pursued as discrete therapeutic targets for drug modulation.

Other names

Buffer solutionBuffer systempH buffer