keratin

[ker-uh-tin]

noun

a scleroprotein or albuminoid substance, found in the dead outer skin layer, and in horn, hair, feathers, hoofs, nails, claws, bills, etc.

Origin of keratin

First recorded in 1840–50; kerat- + -in²

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for keratin

Contemporary Examples of keratin

Rhino horns are made of keratin, the same protein found in our fingernails.
‘Zoobiquity’: What Animals Can Teach Us About Our Health
Carl Zimmer
June 17, 2012

Historical Examples of keratin

Keratin is particularly rich in sulphur, and is quite insoluble in cold water.
Principles and Practice of Fur Dressing and Fur Dyeing
William E. Austin
Keratin, a substance forming the chief constituent in the hair, nails, and horn of animals.
The Nuttall Encyclopaedia
Edited by Rev. James Wood

British Dictionary definitions for keratin

keratin

ceratin

noun

a fibrous protein that occurs in the outer layer of the skin and in hair, nails, feathers, hooves, etc

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for keratin

basic substance of horns, nails, feathers, etc., 1847, from Greek keras (genitive keratos) "horn" (see kerato-) + chemical suffix -in (2).

keratin in Medicine

keratin

[kĕr′ə-tĭn]

Any of a group of scleroproteins or albuminoids that contain large amounts of sulfur and are the chief structural constituents of hair, nails, and other horny tissues.

keratin in Science

keratin

[kĕr′ə-tĭn]

Any of a class of tough, fibrous proteins that are the main structural component of hair, nails, horns, feathers, and hooves. Keratins are rich in sulfur-containing amino acids, especially cysteine. Individual keratin molecules are entwined helically around each other in long filaments, which are cross-linked by bonds between sulfur atoms on different chains. The twining and cross-linking produce strength and toughness.