a scleroprotein or albuminoid substance, found in the dead outer skin layer, and in horn, hair, feathers, hoofs, nails, claws, bills, etc.
- keratan sulfate,
- keratin pearl,
Origin of keratin
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
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|Carl Zimmer|June 17, 2012|DAILY BEAST
Keratin, a substance forming the chief constituent in the hair, nails, and horn of animals.The Nuttall Encyclopaedia|Edited by Rev. James Wood
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
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
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.