Enzymes: organic compounds (Proteins) that are produced by living cells to speed up & regulate the rate of rexn in & outside the cells & allow life to proceed at ordinary temp. Uses:Medical treatment:- Enzyme streptokinase is used in dissolving blood clot. Genetic engineering:- Restriction endonuclease and ligases. Cleaning of hides:- Cleaning of meat and viscera with the aid of protease. Clearing of juices:- Pectinase is used for juice clarification. Alcoholic drinks:- Zymase is used in the preparation of fermented alcoholic beverage. Cheese formation:- Enzyme rennin from calf’s stomach used in making cheese. How enzyme works or speed up the reaction. Activation energy:- is the amount of energy necessary to initiate the chemical reaction. They work to lower down the activation energy thus speeds up the reaction to achieve early products. Nomenclature:1. These are named by adding suffix “ase” to the root word. Lipase, protease etc. 2. According to type of reaction catalysed. Dehydrogenase catalyse removal of hydrogen. 3. A new method consist of two part. First indicating substrate and second indicating the type of reaction catalysed. (DNA polymerase: synthesis of DNA) 4. Some named after their source. E.g. papain from papaya. 5. Some named as “IN” e.g. pepsin and trypsin as these are classified prior to modern nomenclature of classification. Example: Presence of enzyme make the process convenient can be sited through these examples. 1. The oxidation of fatty acid to carbon di oxide and water is not a gentle process in a test tube- extremes of high temperature, pH and corrosive chemicals are required. Yet in the body; such a reaction takes place smoothly and rapidly within a narrow range of pH and temperature. 2. In the laboratory, the average protein must be boiled for about 24 hours in a 20% HCl solution to achieve a complete breakdown. Yet in the body; the breakdown takes place in four hours or less under mild conditions of temperature and pH.