pepsin

pepsin

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.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"pepsin." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"pepsin." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1E1-pepsin.html

"pepsin." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-pepsin.html

Learn more about citation styles

pepsin

pepsin enzyme contained in the gastric juice. XIX. — G., f. Gr. pépsis digestion, f. *pep- cook, digest; see -IN.
So peptic digestive. XVII. — Gr. peptikós, f. peptós cooked, digestive. peptone XIX. — G. pepton — Gr. peptón, n. of peptós.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

T. F. HOAD. "pepsin." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

T. F. HOAD. "pepsin." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O27-pepsin.html

T. F. HOAD. "pepsin." The Concise Oxford Dictionary of English Etymology. 1996. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O27-pepsin.html

Learn more about citation styles

pepsin

pepsin An enzyme in the gastric juice which hydrolyses proteins to give smaller polypeptides, known as peptones; an endopeptidase. Active only at acid pH, 1.5–2.5. Secreted as the inactive precursor pepsinogen, which is activated by acid.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

DAVID A. BENDER. "pepsin." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

DAVID A. BENDER. "pepsin." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O39-pepsin.html

DAVID A. BENDER. "pepsin." A Dictionary of Food and Nutrition. 2005. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O39-pepsin.html

Learn more about citation styles

pepsin

pepsin (pep-sin) n. an enzyme in the stomach that begins the digestion of proteins by splitting them into peptones (see peptidase). It is produced by the action of hydrochloric acid on pepsinogen, which is secreted by the gastric glands.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"pepsin." A Dictionary of Nursing. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"pepsin." A Dictionary of Nursing. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O62-pepsin.html

"pepsin." A Dictionary of Nursing. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-pepsin.html

Learn more about citation styles

pepsin

pepsin Digestive enzyme secreted by glands of the stomach wall as part of the gastric juice. In the presence of hydrochloric acid it catalyzes the splitting of proteins in food into polypeptides. See also peptide

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"pepsin." World Encyclopedia. 2005. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"pepsin." World Encyclopedia. 2005. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O142-pepsin.html

"pepsin." World Encyclopedia. 2005. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-pepsin.html

Learn more about citation styles

pepsin

pep·sin / ˈpepsin/ • n. Biochem. the chief digestive enzyme in the stomach, which breaks down proteins into polypeptides.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"pepsin." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"pepsin." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O999-pepsin.html

"pepsin." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-pepsin.html

Learn more about citation styles

pepsin

pepsin An enzyme that catalyses the breakdown of proteins to polypeptides in the vertebrate stomach. It is secreted as an inactive precursor, pepsinogen.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"pepsin." A Dictionary of Biology. 2004. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"pepsin." A Dictionary of Biology. 2004. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O6-pepsin.html

"pepsin." A Dictionary of Biology. 2004. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-pepsin.html

Learn more about citation styles

Free newspaper and magazine articles

Gene encoding the group B streptococcal protein R4, its presence in clinical...
Magazine article from: Indian Journal of Medical Research; 5/1/2004
Pepsin prosegment-catalyzed folding and inhibition...
Magazine article from: Biochemistry and Cell Biology; 4/1/2010
Insight into the kinetic folding/unfolding barrier of the...
Magazine article from: Biochemistry and Cell Biology; 4/1/2010

Facts and information from other sites

pepsin images
pepsin. Wikimedia Commons (Public Domain)