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pepsin
The Columbia Encyclopedia, Sixth Edition | Date: 2008
pepsin enzyme produced in the mucosal lining of the stomach that acts to degrade protein. Pepsin is one of three principal protein-degrading, or proteolytic, enzymes in the digestive system , the other two being chymotrypsin and trypsin . The three enzymes were among the first to be isolated in crystalline form. During the process of digestion, these enzymes, each of which is particularly effective in severing links between particular types of amino acids, collaborate to break down dietary proteins to their components, i.e., peptides and amino acids , which can be readily absorbed by the intestinal lining. In the laboratory studies pepsin is most efficient in cleaving bonds involving the aromatic amino acids, phenylalanine, tryptophan, and tyrosine. Pepsin is synthesized in an inactive form by the stomach lining; hydrochloric acid, also produced by the gastric mucosa, is necessary to convert the inactive enzyme and to maintain the optimum acidity ( p H 1-3) for pepsin function. Pepsin and other proteolytic enzymes are used in the laboratory analysis of various proteins; pepsin is also used in the preparation of cheese and other protein-containing foods.
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The Columbia Encyclopedia, Sixth Edition 2008
The Columbia Encyclopedia, Sixth Edition. Copyright 2008 Columbia University Press
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Related entries from encyclopedias, dictionaries, and thesauruses
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pepsin
Britannica Concise Encyclopedia
... pepsinogen, a zymogen (enzyme precursor) converted to pepsin by the hydrochloric acid in gastric juice. Pepsin is active only in the acid environment of the stomach ... by digesting the gelatin layer that holds the silver. pepsin pepsin pepsin
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pepsin, vegetable
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pepsin, vegetable See papain .
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vegetable pepsin
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vegetable pepsin See papain .
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gastric secretion
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... infants) and lipase, the inactive precursor of pepsin (pepsinogen), intrinsic factor , mucin ... the gastric mucosa, and is activated to pepsin by either gastric acid or the action of existing pepsin; it is a proteolytic enzyme. The only function ...
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gastric juice
The Columbia Encyclopedia, Sixth Edition
... constituents are the digestive enzymes pepsin and rennin (see rennet ), hydrochloric acid, and mucus. Pepsin converts proteins into simpler, more easily ... provides the acid environment in which pepsin is most effective. Rennin aids the digestion ...
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