Without enzymes, our body chemistry would not occur, and life would not exist. This illustrates the impressive power of enzymes as catalysts. Remember that catalysts increase the rate of a reaction, but are not themselves consumed or produced by the reaction. Also, they do not change the equilibrium constant of a reaction. These statements are true of enzymes as well as other types of catalysts.
Enzymes differ from simple catalysts another very important way.
Enzymes are much more specific. Amylase, a digestive enzyme, will hydrolyze starch, but not cellulose. Both molecules are polymers of glucose. They differ in the orientation of one bond at the junction of glucose units. This broader specificity is useful in the case of an enzyme like papain which is important in protein digestion.