Which component is commonly known to help control pH in biological systems?

Buffers are crucial components in biological systems, serving the specific purpose of maintaining the stability of pH levels. They do this by either absorbing excess hydrogen ions (H⁺) when the solution becomes too acidic or releasing them when the solution is too basic. This ability to resist changes in pH is vital for many biochemical processes that are pH-sensitive, including enzyme activity and metabolic pathways.

In contrast, while salts can influence the ionic balance in a solution, they do not specifically control pH. Water serves as a solvent and medium for various reactions but does not actively regulate pH. Acids, on the other hand, lower pH when dissolved in water and can destabilize pH rather than maintain it, making them unsuitable for control in a biological context. Thus, the role of buffers is essential for the dynamic equilibrium of pH in biological systems.