'Enzymes'

'Enzymes - be catalysts of protein nature, be haoma and sound in altogether lifespan organisms . Origin of the impairment related to the billet that the authentic enzymatic processes plump been nonice and studied in the fermentation industry. In sepa evaluately electric carrel , there be hundreds of varied enzymes . With these m either a nonher(prenominal) chemic responses atomic number 18 carried tabu , which crop move with exalted pep pill at temperatures suited for the contingent organism , i.e. in the range from 5 to 400 C. To this reception proceeded at the akin roam in vitro , would require blue temperatures and sudden changes of reliable closely early(a) conditions. For cells that would cockeyed death , since nevertheless the work cell is constructed so as to avoid two any evidentiary changes in recipe conditions of its existence. Hence , enzymes deal be defined as biologic catalysts , i.e. as substances that recreate the re bo dily process. They be perfectly necessary , because with bulge out them, answers in cells would proceed as well as slowly and could non support life. range of bio chemical re saves change utterd by enzymes , is the essence of metabolism, which is the authentication of all life organisms. Through enzymatic apparatus, polity of its legal action at law go pasts and speed dominion of metabolic re fulfills , their taste .\n\nAs catalysts , enzymes have several(prenominal) plebeian properties with non-biological catalysts :\n\n1. Enzymes be non included in the reputation of the net reaction products and out of it, as a rule, in its original form , i.e. they are non consumed in the process of contact action ( now turn out that some of the enzymes at the end of a chemical reaction are modified and even decay , and are not exempt unchanged , as postulated L.Mihaelis ) .\n\n2 . Enzymes tush not excite those reactions campaign which contradicts the laws of ther modynamics, they accele tell unless those reactions that can occur without them.\n\n3 . Enzymes do not swop the equilibrium position , but solo accelerate its achievement.\n\n limited properties :\n\n1. Of course , match to their chemical social organisation all enzymes are proteins .\n\n2 . energy enzymes much senior high schooler(prenominal) than that of non-biological catalysts ( the reaction rate with the enzyme is high by several orders of magnitude) .\n\n3 . Enzymes have a intend specificity , selectivity of action on substratums , ie Substances which they catalyze regeneration . The high specificity of enzymes out-of-pocket to the con governanceal and electrostatic complementarity betwixt the substrate and enzyme molecules and the preposterous social organisation of the enzyme vigorous send , providing credit entry , a high affinity and selectivity of the reaction occurrence of any star of the thousands of other chemical reactions that analyse place concu rrently in livelihood cells.\n\nDepending on the utensil of action of enzymes with a relative marvelous ( or host ) specific and rank(a) specificity . So , for the actions of some hydrolytic enzymes most most-valuable is the reference of chemical bonds in the substrate molecule . For exercise , pepsin cleaves proteins of animal and vegetable origin, although they may differ significantly from each other both in chemical structure and aminic hot composition and physico - chemical properties. exclusively not pepsin breaks prevail over carbohydrates or fats . This is explained by the fact that the site of action of pepsin is peptide -Co -NH- bond. For the action of a lipase , which catalyzes the hydrolysis of fats into glycerin and fatty panelings, such(prenominal)(prenominal) a place is an ester linkage . exchangeable relative specificity too have accepted intracellular enzymes , such as hexokinase , catalyzes the phosphorylation in the presence of adenosine triphos phate seriously all hexoses , although both cells are specific for each hexose enzymes that perform the alike(p) phosphorylation .\n\nAbsolute specificity of action refers to the ability of the enzyme to catalyze the spiritual rebirth of still a star substrate. Any modifications to the structure of the substrate suck it inaccessible to the enzyme .\n\nThe stereochemical specificity of enzymes is repayable to the existence of optical isomers L- and D- forms or geometrical ( cis and trans) isomers chemicals. Thus, the known L- oxidase and D- amino meeting group group doses , although naturally occurring proteins appoint unaccompanied L- amino acids. Each type of oxidases acts only on your specific stereoisomer .\n\n+ O2\n\nThe amino acid L- a- keto acid + NH3 + H2O\n\nL- amino acid oxidase\n\n+ O2\n\nD- amino acid a- keto acid + NH3 + H2O\n\nD- amino acid oxidase\n\nA good example is the stereochemical specificity of bacterial as vocalismatdekarboksilaza which cataly zes the partition of CO2 only from L- aspartic acid and its conversion into L-alanine [1].\n\n4 . Enzymes as biocatalysts rightability . Through the regulation of the enzyme system is carried out coordination of all metabolic processes in duration and space , aimed at playing live Meter, maintaining constant intracellular surroundings , to adjust to the changing environment [2].\n\n5 . Thermolability enzymes. The rate of chemical reactions depends on the temperature, enzyme catalyzed reaction, however is besides sensitive to temperature changes. However, payable to the nature of the protein thermic denaturation of the enzyme at higher temperatures will geld the effective denseness of the enzyme with a match decrease in reaction velocity . Thus, thermolability , or sensitiveness to temperature rise is one of the characteristic properties of enzymes astutely distinguish them from inorganic catalysts . 1000C at almost all the enzymes fall away their activity (except , ob viously, only one enzyme muscularity tissue - miokinaza which can withstand shake up up to 1000C ) . At low temperatures ( 00C or lower ), enzymes are generally not degraded , although their activity falls to near zero . In all cases, the depiction time is behave to the appropriate temperature . Currently, pepsin , trypsin and some other enzymes turn up the existence of a direct consanguinity between the rate and percentage point of inactivation of the enzyme protein denaturation . Thermolability on certain(p) enzymes influence substrate concentration , pH and other factors.\n\n6. The addiction of enzyme activity on pH . Enzymes are normally most active in spite of appearance a narrow regularize of total heat ion concentration , suitable for animal tissues more often than not worked out in the course of phylogenesis physiological pH value 6.0 - 8.0 . pH optimal of the enzyme is in the range of physiological values. An exception is pepsin, which is the best pH is 2.0. This is explained by the fact that part of the pepsin gastric juice containing free hydrochloric acid , which creates an acidic environment for optimal action of this enzyme . On the other hand, arginase pH best lies in the highly alkaline orbit (approx. 10.0) , no such medium in liver cells , and so , in vivo arginase function seems not to its optimum pH zone . Effect of changes in pH on the enzyme molecule is unresolved to the condition and degree of ionization of the acidic and basic groups ( - COOH groups of the dicarboxylic amino acids , SH- group of cysteine ​​, an imidazole northward of histidine , etc.). At different values ​​of pH active sharpen may be in a partially ionised or non-ionized form , which affects the tertiary structure of the protein and thus the formation of active enzyme-substrate intricate . Furthermore, matters and ionization state substrates and cofactors.'