DehydrogenasesExplanation:Enzymes are the biocatalyst. Most of the enzymes have been classified into different groups based on the type of reactions they CATALYZE. They are as follows- (i) Oxidoreductases/dehydrogenases: The enzymes catalyzing oxidation and reduction between two substrates S and G involving gain or loss of electrons are KNOWN as dehydrogenases. (ii) Transferases: The enzymes catalyzing  the transfer of a GROUP, G (other than hydrogen) between a pair of substrate S and S are known as transferases.(iii) Hydrolases: The enzymes catalyzing hydrolysis of ester, ETHER, peptide, glycosidic, C-C, C-halide or P-N bonds are known as hydrolases.(iv) LYASES: The enzymes that catalyzes the removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds are known as Lyases.(v) Isomerases: The enzymes that catalyzes inter-conversion of optical, geometric or positional isomers are known as isomerases.(vi) Ligases:The enzymes catalyzing, the linking together of two compounds are known as ligases.