Pepsin

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Pepsin \Pep"sin\ (p[e^]p"s[i^]n), n. [Gr. pe`psis a cooking,
     digesting, digestion, fr. pe`ptein, pe`ssein, to cook,
     digest: cf. F. pepsine. Cf. {Dyspepsia}.] (Physiol. Chem.)
     A proteolytic enzyme (MW 34,500) contained in the secretory
     glands of the stomach. In the gastric juice it is united with
     dilute hydrochloric acid (0.2 per cent, approximately) and


     the two together constitute the active portion of the
     digestive fluid. It degrades proteins to proteoses and
     peptides, and is notable for having a very low pH optimum for
     its activity. It is the active agent in the gastric juice of
     all animals.
     [1913 Webster + PJC]
  
     Note: As prepared from the glandular layer of pigs' or
           calves' stomachs it constitutes an important article of
           pharmacy.
           [1913 Webster]

From WordNet (r) 2.0 [wn]:

  pepsin
       n : an enzyme produced in the stomach that splits proteins into
           peptones