ETYM Pref. en- (Greek en in) + Greek zyme leaven.
Any of numerous proteins or conjugated proteins produced by living organisms and functioning as biochemical catalysts. A protein that a living organism uses in the process of degrading a specific compound. The protein serves as a catalyst in the compounds biochemical transformation.
Any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions.
Organic catalyst, especially digestive.
Biological catalyst produced in cells, and capable of speeding up the chemical reactions necessary for life. They are large, complex proteins, and are highly specific, each chemical reaction requiring its own particular enzyme. The enzyme’s specificity arises from its active site, an area with a shape corresponding to part of the molecule with which it reacts (the substrate). The enzyme and the substrate slot together forming an enzyme–substrate complex that allows the reaction to take place, after which the enzyme falls away unaltered.
The activity and efficiency of enzymes are influenced by various factors, including temperature and pH conditions. Temperatures above 60şC/140şF damage (denature) the intricate structure of enzymes, causing reactions to cease. Each enzyme operates best within a specific pH range, and is denatured by excessive acidity or alkalinity.
Digestive enzymes include amylases (which digest starch), lipases (which digest fats), and proteases (which digest protein). Other enzymes play a part in the conversion of food energy into ATP; the manufacture of all the molecular components of the body; the replication of DNA when a cell divides; the production of hormones; and the control of movement of substances into and out of cells.
Enzymes have many medical and industrial uses, from washing powders to drug production, and as research tools in molecular biology. They can be extracted from bacteria and molds, and genetic engineering now makes it possible to tailor an enzyme for a specific purpose.
The most abundant enzyme is ribulose biphosphate carboxylase. It is found in chloroplasts and associated with photosynthesis.
Protein, katalizator reakcija.