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Enzymes are macromolecules that act as organic catalysts in most of the organism's biochemical reactions that have functions indispensable to maintenance and activity of life. It is crucial to note that reaction rates of certain chemical conversions occurring in living organisms are extremely low, and catalysis is necessary to maintain reasonable time of cell development and division. Majority of functional enzymes are proteins, like trypsin, fumarase or papain. The biological processes that occur within all living organisms are chemical reactions, and most are regulated by enzymes. Without enzymes, many of these reactions would not take place at a perceptible rate. Model enzymes are monomeric, globular proteins. Majority of studies on nature of enzymatic reactions were conducted on trypsin, chymotrypsin or amylase. As every protein, to work correctly enzymes require proper folding, and, by consequence, are susceptible to deactivation by denaturation. The key to enzyme activity is a structure called active site. Interactions between residues of polypeptide chain amino acids cause them to create a structure of defined size, shape and sequence. The difference between active site and structural domain is that the latter is able to recognize (recognition site) and process a defined molecule. Whether the interaction between the molecule and recognition site is sterical (shape-based), hydrophobic (chymotrypsin) or ionic (trypsin) it is always specific and temporal. Inhibitors often use specific covalent binding to an active site, which deactivates enzyme permanently. Enzymes catalyze all aspects of cell metabolism. This includes the digestion of food, in which large nutrient molecules (such as proteins, carbohydrates, and fats) are broken down into smaller molecules; the conservation and transformation of chemical energy; and the construction of cellular macromolecules from smaller precursors. Many inherited human diseases, such as albinism and phenylketonuria, result from a deficiency of a particular enzyme. Enzymes also have valuable industrial and medical applications. The fermenting of wine, leavening of bread, curdling of cheese, and brewing of beer have been practiced from earliest times, but not until the 19th century were these reactions understood to be the result of the catalytic activity of enzymes. Since then, enzymes have assumed an increasing importance in industrial processes that involve organic chemical reactions. The uses of enzymes in medicine include killing disease-causing microorganisms, promoting wound healing, and diagnosing certain diseases.
- Format: Inbunden
- ISBN: 9781680945256
- Språk: Engelska
- Utgivningsdatum: 2016-11-30
- Förlag: Arcler Education Inc