The root of an enzyme's name is typically derived from the substrate it reacts with or the type of reaction it catalyzes. The latter forms the basis of the modern nomenclature system for enzymes, known as the International Enzyme Commission, or IEC.
An enzyme is a protein complex that catalyzes biochemical reactions in the body. Its primary function is to speed up the rate of most cellular reactions. An enzyme, typically ending in "-ase," only acts upon a particular compound called a substrate. Enzymes such as lipase and sucrase are named after their substrates, lipid and sucrose, respectively.
The IEC has classified enzymes into six groups: oxidases and dehydrogenases, hydrolases, transferases, lyases, ligases and isomerases. Oxidases and dehydrogenases involve oxidation-reduction processes, hydrolases involve hydrolysis reactions, transferases involve transfer of functional groups, lyases involve addition or removal of double bonds, ligases involve bond formations and isomerases involve isomerization reactions.