Crossword clues for pepsin
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Pepsin \Pep"sin\, n. [Gr. ? a cooking, digesting, digestion, fr. ?, ?, to cook, digest: cf. F. pepsine. Cf. Dyspepsia.] (Physiol. Chem.) An unorganized proteolytic ferment or enzyme 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 is the active agent in the gastric juice of all animals.
Note: As prepared from the glandular layer of pigs' or calves' stomachs it constitutes an important article of pharmacy.
Douglas Harper's Etymology Dictionary
also pepsine, fermin in gastric juice, used medicinally for cases of indigestion, 1844, coined in German (Theodor Schwann, 1835) from Greek pepsis "digestion," from stem pep- (see peptic) + -in (2).
Wiktionary
n. (context enzyme English) A digestive enzyme that chemically digests, or breaks down, proteins into shorter chains of amino acids.
WordNet
n. an enzyme produced in the stomach that splits proteins into peptones
Wikipedia
Pepsin is an enzyme that breaks down proteins into smaller peptides (that is, a protease). It is produced in the stomach and is one of the main digestive enzymes in the digestive systems of humans and many other animals, where it helps digest the proteins in food.
It is one of three principal proteases in the human digestive system, the other two being chymotrypsin and trypsin. During the process of digestion, these enzymes, each of which is specialized in severing links between particular types of amino acids, collaborate to break down dietary proteins into their components, i.e., peptides and amino acids, which can be readily absorbed by the small intestine. Pepsin is most efficient in cleaving peptide bonds between hydrophobic and preferably aromatic amino acids such as phenylalanine, tryptophan, and tyrosine.
Pepsin's proenzyme, pepsinogen, is released by the chief cells in the stomach wall, and upon mixing with the hydrochloric acid of the gastric juice, pepsinogen activates to become pepsin. Pepsin is an aspartic protease, using a catalytic aspartate in its active site.
Usage examples of "pepsin".
In like manner, the glands of the stomach of animals secrete pepsin, as Schiff asserts, only after they have absorbed certain soluble substances, which he designates as peptogenes.
It may be well to premise for the sake of any reader who knows nothing about the digestion of albuminous compounds by animals that this is effected by means of a ferment, pepsin, together with weak hydrochloric acid, though almost any acid will serve.
Although it has long been known that pepsin with acetic acid has the power of digesting albuminous compounds, it appeared advisable to ascertain whether acetic acid could be replaced, without the loss of digestive power, by the allied acids which are believed to occur in the secretion of Drosera, namely, propionic, butyric, or valerianic.
Even if I had tried no other experiments than these, they would have almost sufficed to prove that the glands of Drosera secrete some ferment analogous to pepsin, which in presence of an acid gives to the secretion its power of dissolving albuminous compounds.
We have also seen that butyric acid, which is much more efficacious than propionic or valerianic acids, digests with pepsin at the higher temperature less than a third of the fibrin which is digested at the same temperature by hydrochloric acid.
Now, it is a remarkable fact, which affords additional and important evidence, that the ferment of Drosera is closely similar to or identical with pepsin, that none of these same substances are, as far as it is known, digested by the gastric juice of animals, though some of them are acted on by the other secretions of the alimentary canal.
Oudeni gar eoike to anthropou soma ton epi sarkophagia gegonoton, ou grupotes cheilous, ouk ozutes onuchos, ou traxutes odontos prosestin, ou koilias eutonia kai pneumatos thermotes, trepsai kai katergasasthai dunate to baru kai kreodes all autothen e phusis te leioteti ton odonton kai te smikroteti tou stomatos kai te malakoteti tes glosses kai te pros pepsin ambluteti tou pneumatos, exomnutai ten sarkophagian.
Hundreds of the excited mob press close to the cowering motorman, whose hand is observed to tremble perceptibly as he transfers a stick of pepsin gum from his pocket to his mouth.
The purpose of the following experiments was to determine the digestive activity of liquids containing pepsin, when acidulated with certain volatile acids belonging to the acetic series, in comparison with liquids acidulated with hydrochloric acid, in proportion similar to that in which it exists in gastric juice.
Now, it is a remarkable fact, which affords additional and important evidence, that the ferment of Drosera is closely similar to or identical with pepsin, that none of these same substances are, as far as it is known, digested by the gastric juice of animals, though some of them are acted on by the other secretions of the alimentary canal.
Drosera, 2 , coats of pollengrains not digested by insects, 117 Binz, on action of quinine on white bloodcorpuscles, 201 , on poisonous action of quinine on low organisms, 202 Bone, its digestion by Drosera, 105 Brunton, Lauder, on digestion of gelatine, 111 , on the composition of casein, 115 , on the digestion of urea, 124 , of chlorophyll, 126 , of pepsin, 124 Byblis, 343 C.
Other enzymes are pepsin, found in the stomach, and trypsin and erepsin, found in the intestine.