What is the function of a buffer in a biological context?

In a biological context, a buffer plays a crucial role in maintaining a constant pH level within a solution. pH is a measure of how acidic or basic a solution is, and biological processes often require a very specific pH range to function optimally. Enzymes, for example, have an optimal pH at which they are most active, and deviations can result in decreased activity or denaturation.

Buffers work by either accepting or donating protons (H⁺ ions) in response to changes in concentration, thus resisting changes in the pH of the solution even when acids or bases are added. This is vital for cellular functions and metabolic processes, where pH variations can lead to harmful consequences for the organism. By maintaining a stable pH, buffers ensure that biochemical pathways can operate effectively, thus supporting life processes at the molecular level.

The other options do not accurately describe the primary function of buffers in a biological setting.