keratin(redirected from hard keratin)
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a substance found in the dead outer skin and in horn, hoofs, nails, claws, etc.
Not to be confused with:
carotene – orange fat-soluble pigments found in some plants, such as carrots; vitamin A
Abused, Confused, & Misused Words by Mary Embree Copyright © 2007, 2013 by Mary Embree
1. Any of a class of filamentous proteins that are abundant in the cytoskeleton of vertebrate epithelial cells and are the main constituents of the outer layer of skin and tough epidermal structures such as hair, nails, hooves, feathers, and claws.
2. Material composed principally of keratin proteins.
ke·rat′i·nous (kə-răt′n-əs) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
(Zoology) a fibrous protein that occurs in the outer layer of the skin and in hair, nails, feathers, hooves, etc
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
ker•a•tin(ˈkɛr ə tɪn)
a tough, insoluble protein that is the main constituent of hair, nails, horn, hoofs, etc., and of the outermost layer of skin.
ke•rat•i•nous (kəˈræt n əs) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
A tough, fibrous protein that is the main structural component of hair, nails, horns, feathers, and hooves.
Did You Know? Nature ingeniously uses the same chemicals to perform a wide variety of functions in living things. An example is the group of closely related proteins known as the keratins. When nature wants something hard and tough for an animal, it turns to keratins. Your nails and hair are made mostly of a kind of keratin, and so are a dog's claws, a bird's beak, and a goat's horns. Even the hard material called baleen that some whales have in their mouths to help them eat is made of a variety of keratin. All proteins are strings of amino acids, and the keratins' secret is the amino acid known as cysteine. This amino acid tends to form strong bonds with other cysteines in the protein. The different keratins vary in hardness, depending on how many cysteine bonds are present. The bonds are what make the keratins tough as, well, nails.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A hard, waterproof protein found in the epidermis, hair, and nails.
Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited
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|Noun||1.||keratin - a fibrous scleroprotein that occurs in the outer layer of the skin and in horny tissues such as hair, feathers, nails, and hooves|
feather, plumage, plume - the light horny waterproof structure forming the external covering of birds
hair - a covering for the body (or parts of it) consisting of a dense growth of threadlike structures (as on the human head); helps to prevent heat loss; "he combed his hair"; "each hair consists of layers of dead keratinized cells"
horn - the material (mostly keratin) that covers the horns of ungulates and forms hooves and claws and nails
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
keratin[ˈkɛrətɪn] n → cheratina
Collins Italian Dictionary 1st Edition © HarperCollins Publishers 1995
n. queratina, proteína orgánica insoluble, elemento componente de las uñas, la piel y el cabello.
English-Spanish Medical Dictionary © Farlex 2012
English-Spanish/Spanish-English Medical Dictionary Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.