True!
A buffer is a solution that helps in resisting the change in the pH when a acid or base is added to it. Cells contain a lot of different organelle inside them. Each organelle performs a different kind of function and thus has a pH different from the cytoplasm, example mitochondria which has a pH lower than that of the cytoplasm. These organelle maintain a pH buffer within them to resist a change in the environment that will hamper the functioning of proteins in it. Cells like the organelle also maintain a pH buffer in their cytoplasm to resist changes in the pH level due to pH changes in the external environment. This is a way in which the cellular homeostasis takes place.