pepsin

views updated Jun 27 2018

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

World Encyclopedia

pepsin

views updated May 23 2018

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.

The Concise Oxford Dictionary of English Etymology T. F. HOAD

pepsin

views updated May 29 2018

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.

A Dictionary of Food and Nutrition DAVID A. BENDER

pepsin

views updated Jun 11 2018

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

The Oxford Pocket Dictionary of Current English

pepsin

views updated May 23 2018

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.

A Dictionary of Nursing

pepsin

views updated May 18 2018

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

A Dictionary of Biology