keratin ker"a*tin, n. [Gr. ke`ras, -atos, horn.] (Physiol. Chem.) A sulfur-containing fibrous protein constituting the main structural protein of hard epidermal tissues, such as horn, hair, feathers, nails, claws, hoofs, and the like. It is an insoluble substance, and, unlike elastin, is not dissolved even by gastric or pancreatic juice. By decomposition with sulphuric acid it yields leucine and tyrosine plus various other acid-stable amino acids. The amino acid composition varies, but it usually has a high percentage of cystine, which stabilizes and insolubilizes the protein by forming intrachain linkages. A softer form of keratin is present in the epidermis and whalebone. Called also {epidermose}. [1913 Webster +PJC]

The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Keratīn — Keratīn, so v.w. Hornsubstanz, s.u. Horn …   Pierer's Universal-Lexikon

  • Keratīn — (v. griech. kéras, Horn; Hornstoff), die Substanz des Horngewebes, die als Neurokeratin auch einen Teil der Scheide der markhaltigen Nerven bildet, und sich außerdem in den Eischalenhäuten der Wirbeltiere, in den Schalen der Schnecken, den Kokons …   Meyers Großes Konversations-Lexikon

  • Keratin — Keratīn, Hornstoff, Hauptbesandteil aller Horngebilde (Horn, Nägel, Federn etc.), aus Kohlenstoff, Wasserstoff, Stickstoff, Sauerstoff und Schwefel bestehend, löslich in Alkalien und konzentrierter Essigsäure …   Kleines Konversations-Lexikon

  • Keratin — Keratin, Hornsubstanz …   Herders Conversations-Lexikon

  • keratin — basic substance of horns, nails, feathers, etc., 1847, from Gk. keras (gen. keratos) horn (see KERATO (Cf. kerato )) + chemical suffix IN (Cf. in) (2) …   Etymology dictionary

  • keratin — keràtīn m <G keratína> DEFINICIJA fiziol. bjelančevina, od koje se sastoji vanjski sloj kože, dlake, nokti, rogovi, papci, perje; rožina ETIMOLOGIJA kerat (o) + in …   Hrvatski jezični portal

  • keratin — ► NOUN ▪ a fibrous protein forming the main constituent of hair, feathers, hoofs, claws, and horns. ORIGIN from Greek keras horn …   English terms dictionary

  • keratin — [ker′ə tin] n. [ KERAT(O) + IN1] a tough, fibrous, insoluble protein forming the principal matter of hair, nails, horn, etc. keratinous [kə rat′ n əs] adj. keratinoid [ke rat′inoid΄] …   English World dictionary

  • Keratin — Not to be confused with kerogen, carotene, chitin, or creatine. Microscopy of keratin filaments inside cells. Keratin refers to a family of fibrous structural proteins. Keratin is the key structural material making up the outer layer of human… …   Wikipedia

  • keratin — /ker euh tin/, n. a scleroprotein or albuminoid substance, found in the dead outer skin layer, and in horn, hair, feathers, hoofs, nails, claws, bills, etc. [1840 50; KERAT + IN2] * * * Fibrous structural protein of hair, nails, hooves, wool,… …   Universalium

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