3. Hydrolases
👉Lysosomes
These are membrane bound vesicular structures formed by the process
of packaging in the golgi apparatus. The isolated lysosomal vesicles
have been found to be very rich in almost all types of hydrolytic
enzymes (hydrolases – lipases, proteases, carbohydrases) optimally
active at the acidic pH. These enzymes are capable of digesting
carbohydrates, proteins, lipids and nucleic acids.
👉Classification and Nomenclature of Enzymes
Thousands of enzymes have been discovered, isolated and studied. Most
of these enzymes have been classified into different groups based on the
type of reactions they catalyse. Enzymes are divided into 6 classes each
with 4-13 subclasses and named accordingly by a four-digit number.
👉Oxidoreductases/dehydrogenases: Enzymes which catalyse
oxidoreduction between two substrates S and S’ e.g.,
S reduced + S’ oxidised ® S oxidised + S’ reduced.
👉Transferases: Enzymes catalysing a transfer of a group, G (other than
hydrogen) between a pair of substrate S and S’ e.g.,
S - G + S’ ® S + S’ - G
👉Hydrolases: Enzymes catalysing hydrolysis of ester, ether, peptide,
glycosidic, C-C, C-halide or P-N bonds.
👉Lyases: Enzymes that catalyse removal of groups from substrates by
mechanisms other than hydrolysis leaving double bonds.
👉Isomerases: Includes all enzymes catalysing inter-conversion of optical,
geometric or positional isomers.
👉Ligases: Enzymes catalysing the linking together of 2 compounds, e.g.,
enzymes which catalyse joining of C-O, C-S, C-N, P-O etc. bonds.
