- 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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for keratin
Rhino horns are made of keratin, the same protein found in our fingernails.‘Zoobiquity’: What Animals Can Teach Us About Our Health
June 17, 2012
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
- 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
Online Etymology Dictionary, © 2010 Douglas Harper
- 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.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.