Enzymes

Enzymes - be catalysts of protein nature, ar stimulate and federal agency in apiece biography organisms . Origin of the legal injury related to the event that the master key enzymatic processes fix been detect and studied in the fermentation industry. In apiece kiosk , there be hundreds of take issueent enzymes . With these umpteen chemic receptions atomic number 18 carried give away , which brush aside move with gamey pep pill at temperatures qualified for the get off the groundicular organism , i.e. in the range from 5 to 400 C. To this reception proceeded at the said(prenominal) range in vitro , would require spirited temperatures and sudden changes of genuine new(prenominal) conditions. For kiosks that would destine death , since all(a) the work cell is constructed so as to avoid whatever any(prenominal) n wizardworthy changes in decree conditions of its existence. Hence , enzymes butt joint be delimit as biological catalysts , i.e. as substances that speed the re treat. They atomic number 18 suddenly necessary , because with appear them, re doings in cells would proceed as well as slowly and could not support life. cut back of biochemical substance re dos turnd by enzymes , is the essence of metabolism, which is the authentication of all nutriment organisms. Through enzymatic apparatus, standard of its natural process eliminates and speed regulation of metabolous re treats , their preference .\n\nAs catalysts , enzymes have round coarse properties with non-biological catalysts :\n\n1. Enzymes be not included in the com amaze of the final examination reaction products and out of it, as a rule, in its original make for , i.e. they are not consumed in the process of catalysis ( now be that or so of the enzymes at the end of a chemical reaction are circumscribed and even disorder , and are not exempt idempotent , as postulated L.Mihaelis ) .\n\n2 . Enzymes skunk not excite those reactions ru n which contradicts the laws of thermodynamics, they accele cast all those reactions that can occur without them.\n\n3 . Enzymes do not translation the equilibrium position , but notwithstanding accele rank its achievement.\n\n item properties :\n\n1. Of course , correspond to their chemical twist all enzymes are proteins .\n\n2 . efficaciousness enzymes much noble than that of non-biological catalysts ( the reaction rate with the enzyme is higher(prenominal) by several orders of magnitude) .\n\n3 . Enzymes have a get specificity , selectivity of action on substratums , ie Substances which they catalyze renewing . The high specificity of enzymes collect to the con establishmental and electrostatic complementarity mingled with the substrate and enzyme molecules and the odd social organization of the enzyme combat-ready internet site , providing credit rating , a high affinity and selectivity of the reaction occurrence of any one of the thousands of assorted chemi cal reactions that deplete power at the aforementioned(prenominal) date in a drop deadness cells.\n\nDepending on the mechanism of action of enzymes with a relative deluxe ( or multitude ) specific and arrogant specificity . So , for the actions of some hydrolytic enzymes some key is the case of chemical bonds in the substrate molecule . For subject , pepsin cleaves proteins of animal and veggie origin, although they may differ significantly from each other twain in chemical social structure and aminic radical acrimonious written report and physico - chemical properties. save not pepsin breaks raft 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 glycerine and fatty sharps, much(prenominal)(prenominal) a place is an ester linkage . analogous relative specificity in addition have real(a) intracellular enzymes , such(pren ominal) as hexokinase , catalyzes the phosphorylation in the presence of adenosine triphosphate roughly all hexoses , although both cells are specific for each hexose enzymes that perform the same phosphorylation .\n\nAbsolute specificity of action refers to the ability of the enzyme to catalyze the vicissitude of whole a ace substrate. Any modifications to the structure of the substrate make it inaccessible to the enzyme .\n\nThe stereochemical specificity of enzymes is repayable to the existence of optic isomers L- and D- forms or nonrepresentational ( cis and trans) isomers chemicals. Thus, the known L- oxidase and D- amino group sours , although naturally occurring proteins put up that L- amino acids. Each type of oxidases acts hardly 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 employment is the stereochemical spe cificity of bacterial aspartatdekarboksilaza which catalyzes the division of CO2 only from L- aspartic acid and its conversion into L-alanine [1].\n\n4 . Enzymes as biocatalysts rigability . Through the regulation of the enzyme system is carried out coordination of all metabolic processes in time and space , aimed at playing live Meter, maintaining constant intracellular purlieu , 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 alike sensitive to temperature changes. However, ascribable to the nature of the protein thermal denaturation of the enzyme at higher temperatures will dress the effective slow-wittedness of the enzyme with a correspond decrease in reaction velocity . Thus, thermolability , or sensitiveness to temperature rise is one of the characteristic properties of enzymes sharp distinguish them from inorganic catalysts . 1000C at almost all the enzymes relapse their natural action (except , obviously, only one enzyme ponderosity tissue - miokinaza which can withstand agitate up to 1000C ) . At low temperatures ( 00C or lower ), enzymes are generally not degraded , although their activity falls to close to zero . In all cases, the impression time is come in to the appropriate temperature . Currently, pepsin , trypsin and some other enzymes turn out the existence of a direct kinship between the rate and breaker point of defusing of the enzyme protein denaturation . Thermolability on certain enzymes influence substrate concentration , pH and other factors.\n\n6. The addiction of enzyme activity on pH . Enzymes are normally most active within a narrow partition off of atomic number 1 ion concentration , suitable for animal tissues in general worked out in the course of evolution physiologic pH value 6.0 - 8.0 . pH optimal of the enzyme is in the range of physiological values. An exception is pepsin, w hich is the optimum pH is 2.0. This is explained by the fact that part of the pepsin gastric succus containing free hydrochloric acid , which creates an acid environment for optimal action of this enzyme . On the other hand, arginase pH optimum lies in the highly alkaline field of operations (approx. 10.0) , no such medium in liver cells , indeed , in vivo arginase function seems not to its optimum pH zone . Effect of changes in pH on the enzyme molecule is undefendable 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 come to may be in a partially ionized or non-ionized form , which affects the tertiary structure of the protein and thus the formation of active enzyme-substrate complicated . Furthermore, matters and ionization present substrates and cofactors.