Classification of Enzymes Based on Where They Work

Classification of enzymes 1. Classification of enzymes based on where they work a) Endoenzymes Endoenzymes are also called intracellular enzymes, namely enzymes that work inside cells. Generally, it is an enzyme used for synthesis processes in cells and for the formation of energy (ATP) which is useful for cell life processes, for example in the respiration process. b) Exoenzymes Exoenzymes are also called extracellular enzymes, namely enzymes that work outside the cell. Generally functions to "digest" the substrate by hydrolysis, to make simpler molecules with a lower BM so that they can pass through the membrane. cell. The energy released in substrate breakdown reactions outside the cell is not used in the cell's life processes. 2. Classification of enzymes based on catalytic power Based on the type of reaction catalyzed, enzymes can be divided into several groups, namely 150: a) Oxidoreductase This enzyme catalyzes oxidation-reduction reactions, which is the transfer of electrons, hydrogen or oxygen. Examples include the enzymes electron transfer oxidase and hydrogen peroxidase (catalase). Oxidase, oxygenase, hydoxylase and dehydrogenase enzymes are several types of electron transfer oxidase enzymes. b) Transferase Transfer of molecular groups from one molecule to another molecule catalyzrd by transferase. For example, several enzymes are as follows; Transaminase is a transferase that moves amine groups, Transphosphorylase is a transferase that moves phosphate groups, Transacylase is a transferase that moves acyl groups. c) Hydrolase Hydrolysis reactions catalyzes by this enzyme, for example the enzyme being carboxylesterase is a hydrolase that hydrolyzes carboxyl ester groups. Lipase is a hydrolase that hydrolyzes fats (lipid ester) d) Lyase Lyase catalyze the removal or addition of groups from a molecule without going through a hydrolysis process, for example: L malate hydrolyase (fumarase), which is an enzyme that catalyzes the reaction of taking water from malate to produce fumarate, Decarboxyliase (decarboxylase), which is an enzyme that catalyzes the taking reaction carboxyl group. e) Isomerase Isomerase includes enzymes that catalyze isomerization reactions, namely: Rasemase, converts l-alanine D-alanine, Epimerase, converts D-ribulose-5-phosphate D-xylulose5phosphate, Cis-trans isomerase, converts transmetinal cisrentolal, Intramolecular ketol isomerase, converts glyceraldehyde-3phosphate dihydroxy acetone phosphate, Intramolecular transferase or mutase converts methylmalonyl-CoAsuccinyl-CoA f) Ligase This enzyme catalyzes the reaction of joining two molecules with the release of the pyrophosphate molecule from the nucleoside triphosphate, for example the enzyme acetate=CoASH ligase 3. Other enzymes with different nomenclature There are several enzymes whose names are not according to the method above, for example the enzymes pepsin, triosine, and so on as well as enzymes including permease enzymes. 4. Classification of enzymes based on how they are formed a) Constitutive enzymes In cells there are enzymes which are part of the normal cell structure, so these enzymes are always present generally in fixed amounts in living cells. However, there are enzymes whose quantity is influenced by the level of the substrate for example the amylase enzyme. Meanwhile, the number of enzymes that play a role in the respiration process is not influenced by the levels of the substrate. b) Adaptive enzymes Changes in the microbial environment can induce the formation of certain enzymes. Induction causes the rate of synthesis of an enzyme to be stimulated several thousand times. Adaptive enzymes are enzymes whose formation is stimulated by the presence of a substrate. An example is the beta galactosidase enzyme produced by E. coli bacteria grown in a medium containing lactose. Initially, E. coli cannot use lactose so initially there is no visible growth (lag phase/long adaptation phase) after some time new growth appears.