Many biochemical reactions, especially enzyme catalyses, are similar to electrochemical reactions. In electrochemical reactions tbe substrate is either oxidized or reduced on the eleçtrodes by electron transfers. Developments in electroorganic chemistry showed that many of the chemical bonds can be cleaved electrochemically. Especically R—O, C—X, Ar—O, N—H, C=N, C—S, C—O, C—N, C--S and C—C bonds and some other heteroatom bondş are known to be cleaved electrochemically. As a resultof those cleaveges dimerizations, polymerizations, rearrengements, substitutions, remo valof functional groups, ete. occur. When we examinc the biochemical reactions of the enzymes they result in reduetion, oxydation> cleavage, addition, rearrengement and polymerization, similar to electrochemical reactions. In the present work, enzymes which are classified as ovidoreduetases, transferases, hydro- lases, lyases, isomerases and ligases are compared with electrochemical reactions.