Why ph affects enzyme activity

While some of the presentation may seem somewhat dated, the basic concepts are still helpful for researchers who must use enzymes but who have little background in enzymology. Enzymes are affected by changes in pH. The most favorable pH value - the point where the enzyme is most active - is known as the optimum pH. This is graphically illustrated in Figure Extremely high or low pH values generally result in complete loss of activity for most enzymes.

As with activity, for each enzyme there is also a region of pH optimal stability. Enzyme activity is at its maximum value at the optimum pH. As the pH value is increased above or decreased below the optimum pH the enzyme activity decreases. At very acidic and alkaline pH values the shape of the enzyme is altered so that it is no longer complementary to its specific substrate. This effect can be permanent and irreversible and is called denaturation. The diagram below shows what happens to an enzyme when denaturation occurs.

What Is Lipase? Where Does Chemical Digestion Occur? What Is the Role of Enzymes in Metabolism? PH Levels of Catalase. The Activity of the Lactase Enzyme. What Is the Goal of Homeostasis?