The pH of the blood must be kept in a narrow range (7.2-7.4) for continued survival. The buffered region for blood is not always optimum for other situations. Enzymes have optimum temperature and optimum pH ranges as well. The optimum pH for the action of pepsin in the stomach is pH 2-3. In the adjoining small intestine, enzymes function at a higher pH. Biochemists will keep a specific tissue in a buffer [local] that corresponds to need. Buffers keep the proteins from denaturing and the enzymes functional. A table of common buffers [local]is provided.

Homeostatic [local] processes help the body maintain electrolytes and pH balance. The body is able to maintain pH balance by action of respiration and renal function.