Enzymes catalysing a transfer of G group, (other than hydrogen) between a pair of substrates, S and S′ are known as transferases. S−G+S#⟶S+S#−G - Ligases catalyse the linking together of 2 compounds such as C−O,C−S,C−N bonds etc - Lyases catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds Hydrolases are enzymes that catalyse hydrolysis of ester, ether, peptide, glycosidic, C−C,C− halide or P−N bonds.