What is one key function of a buffer in biological systems?

A buffer is essential in biological systems due to its primary function of maintaining homeostasis of pH levels. Biological processes are highly sensitive to pH changes, as many biochemical reactions occur optimally within specific pH ranges. Buffers help stabilize the pH by neutralizing excess acids or bases, thus ensuring that the environment remains conducive for enzymatic activities and other physiological processes.

For instance, in human blood, the bicarbonate buffer system plays a crucial role in regulating pH, allowing it to remain within a narrow range around 7.4. This stability is vital for overall metabolic functions and the proper performance of various biological reactions. The correct function identified in the context underlines the importance of buffers in sustaining the delicate balance necessary for life.