# How do buffers work to maintain pH?

$p H = p {K}_{a} + {\log}_{10} \left\{\frac{\left[{A}^{-}\right]}{\left[H A\right]}\right\}$
See this older answer. You should review your understanding of the $\text{logarithmic function}$, because this is crucial in understanding how the equation works.
Biological systems are extensively buffered, and in a buffer, the $p H$ of the solution remains tolerably close the to the $p {K}_{a}$ of the original acid.