Enzymes change activity with alterations in pH and temperature. Each enzyme functions most rapidly at a specific pH optimum. When the pH deviates too greatly from the enzyme's optimum, activity slows and the enzyme may be damaged
Enzymes also have optima for maximum activity. If the temperature rises too much above the optimum, an enzyme's structure will be disrupted and its activity lost. This phenomenon is known as denaturation and may be caused by extremes of temperature and pH and also by other factors.