HOW ENZYMES LOWER ACTIVATION ENERGY
Enzymes carry out their function of lowering activation energy by temporarily combining with the chemicals involved in the reaction. These chemicals are called the substrate. Enzymes are specific for their substrate: A particular substrate molecule will combine temporarily with one enzyme type, and the active site of a particular enzyme will fit only one kind of substrate. For example, the enzyme sucrase will attach only to the substrate sucrose. The combination is called the enzyme- substrate complex. When the enzyme and substrate combine, the substrate is changed to a different chemical called the product. The enzyme is not consumed or altered by the reaction.