For example, amylase-enzyme, the hydrolyzing starch with which we already met repeatedly, has the Classification of Enzymes index it is constructed so that in it empty seats for yet not open enzymes are left.
Stereochemical and optical specificity has special value. It is shown only in case of optically active agents, and enzyme is active only in relation to one stereoisomerous form of connection. For example, L-of an arginaz decomposes L-arginin to L- and urea, but does not work on And -. D and L-specificity of oxidases of amino acids is a known example. Stereochemical and optical activity so - can be absolute and relative; for example, the karboksipeptidaza splitting karbobenzoks - glitsil-L-phenylalanine does not affect a substratum with And at all - phenylalanine: on the other hand, the esteraza of pork liver decomposes methyl air of L-of almond acid only twice quicker, than its And - isomer.
One of the most amazing properties of enzymes their specificity. Specificity of enzymes is shown on - to a miscellaneous and can be expressed in different degree. First of all it is necessary to distinguish specificity in relation to a substratum and to type of the chemical reaction catalyzed by enzyme.
Along with only that another, the specificity form which is closely connected with the first expressed in ability of enzyme to attack a substratum only of a certain chemical structure exists the described form of specificity of enzyme in relation to the reaction catalyzed by it also. Sometimes enzyme is capable to affect only the unique substratum, then say that it possesses absolute specificity. Much more often enzyme influences group of the substrata having a similar structure. Such specificity designate group. The so-called stereochemical specificity consisting that enzyme affects a substratum or group of the substrata differing in a special arrangement of atoms in space is of special interest.
Fermentologiya very long had no, is strict the scientific nomenclature of enzymes. Names gave to enzymes on casual signs (trivial nomenclatures, according to the name of a substratum (rational), on a chemical composition of enzyme, at last, as the catalyzed reaction and character of a substratum. Names of such enzymes as pepsin (from Greek pepsin - digestion, trypsin (from a Greek tripsis - I dilute) and papainase can be examples of the trivial nomenclature (from the name of a melon tree of Carica papaja from which juice it is allocated). On action all these enzymes are proteolytic, i.e. accelerate hydrolysis of proteins (protein. The characteristic name was it is given group of the painted intracellular enzymes accelerating oxidation-reduction reactions in a cage - tsitokhroma (from armor. citos - a cage and chroma - color).
ISOMERASES – the enzymes catalyzing transformation of isomerous forms each other, - are carrying out intramolecular transformation of various groups. Treat them not only the enzymes stimulating reactions of mutual transitions of optical and geometrical isomers but also such which can promote transformation in ketoza or to movement of radio communication and others.
Only after contact of enzyme with a substratum chemical groups of the active center (And, In, C) as a result of change of their spatial arrangement come to a condition of strict compliance to a molecule of a substratum.
Presence at the reactionary environment of some ions can activate education active a substratum of a fermental complex, and in this case the speed of fermentativny reaction will be increases. Such substances received the name of activators. Thus the substances catalyzing fermentativny reactions are not directly involved in them. Activity of one enzymes is influenced significantly by concentration of salts in system, other enzymes are not sensitive to presence of ions. However some ions are absolutely necessary for normal functioning of some enzymes. Ions which brake activity of one enzymes are known and are activators for others. Cations of metals are among specific activators: Na +, K+, Rb +, Cs +, Mg2 +, Ca2 +, Zn2 +, Cd2 +, Cr2 +, Cu2 +,