ABSTRACT
Enzymes are biocatalysts and as such their function is to influence the rates of chemical reactions. The enzyme molecule exerts its effective catalytic function by participating directly in the reaction as if it were a reactant. In general, however, where concentrations of enzymes are employed which are several orders of magnitude below that of the substrate(s), the enzyme approaches a true catalyst in nature, and, under these conditions, influences only the rates of chemical reactions and not the final equilibrium state. A quantitative description of enzyme kinetics incorporates all the known chemical laws of catalytic reactions; the rate of the enzymatic reaction can often be adequately expressed in terms of reaction-rate mathematics. A number of theories have been proposed to explain the extraordinarily high effectiveness of enzyme catalysis and the unusual degree of substrate specificity which they display.
