| 释义 |
keratinenUK
keratina 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 Aker·a·tin K0039000 (kĕr′ə-tĭn)n.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.
[Greek keras, kerāt-, horn; see ker- in Indo-European roots + -in.]
ke·rat′i·nous (kə-răt′n-əs) adj.keratin (ˈkɛrətɪn) or ceratinn (Zoology) a fibrous protein that occurs in the outer layer of the skin and in hair, nails, feathers, hooves, etcker•a•tin (ˈkɛr ə tɪn)
n. a tough, insoluble protein that is the main constituent of hair, nails, horn, hoofs, etc., and of the outermost layer of skin. [1840–50; < Greek kerat-, s. of kéras horn + -in1] ker`a•tin•i•za′tion, n. ker′a•tin•ize`, vb ke•rat•i•nous (kəˈræt n əs) adj. ker·a·tin (kĕr′ə-tĭn) 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.keratinA hard, waterproof protein found in the epidermis, hair, and nails.Thesaurus| 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 hoovesceratinfeather, plumage, plume - the light horny waterproof structure forming the external covering of birdshair - 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 nailsalbuminoid, scleroprotein - a simple protein found in horny and cartilaginous tissues and in the lens of the eye |
TranslationskeratinenUK
keratin (kĕr`ətĭn), any one of a class of fibrous proteinprotein,
any of the group of highly complex organic compounds found in all living cells and comprising the most abundant class of all biological molecules. Protein comprises approximately 50% of cellular dry weight.
..... Click the link for more information. molecules that serve as structural units for various living tissues. The keratins are the major protein components of hair, wool, nails, horn, hoofs, and the quills of feathers. These proteins generally contain large quantities of the sulfur-containing amino acidsamino acid
, any one of a class of simple organic compounds containing carbon, hydrogen, oxygen, nitrogen, and in certain cases sulfur. These compounds are the building blocks of proteins.
..... Click the link for more information. , particulary cysteinecysteine
, organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of mammalian protein.
..... Click the link for more information. . The helical keratin molecules twist around each other to form elongated strands called intermediate filaments. The formation of a covalent chemical bondchemical bond,
mechanism whereby atoms combine to form molecules. There is a chemical bond between two atoms or groups of atoms when the forces acting between them are strong enough to lead to the formation of an aggregate with sufficient stability to be regarded as an
..... Click the link for more information. called a disulfide bridge between the sulfer atoms on two cysteins on separate polypeptide chains of keratin allows for the cross-linkage of these chains and results in a fairly rigid aggregate. This phenomenon is seen to be consistent with the physiological role of the keratins, which provide a tough, fibrous matrix for the tissues in which they are found. Human hair is approximately 14% cystine (cysteins cross-linked by disulfide bridges).keratin[′ker·əd·ən] (biochemistry) Any of various albuminoids characteristic of epidermal derivatives, such as nails and feathers, which are insoluble in protein solvents, have a high sulfur content, and generally contain cystine and arginine as the predominating amino acids. keratinA proteinaceous material used as a retarder for plaster.keratin, ceratin a fibrous protein that occurs in the outer layer of the skin and in hair, nails, feathers, hooves, etc.
See keratinkeratinenUK
keratin [ker´ah-tin] a scleroprotein that is the principal constituent of epidermis, hair, nails, horny tissues, and the organic matrix of the enamel of the teeth. Its solution is sometimes used in coating pills when the latter are desired to pass through the stomach unchanged.ker·a·tin (ker'ă-tin), Collective name for a group of proteins that form the intermediate filaments in epithelial cells. Keratins have a molecular weight between 40 kD and 68 kD and are separated one from another by electrophoresis and isoelectric focusing; thus separated, they are sequentially numbered from 1-20, and also subdivided into low, intermediate, and high molecular weight proteins. According to their isoelectric mobility they are either acidic or basic. In general, each acidic keratin protein has its basic equivalent with which it is paired to form the intermediate filaments; some keratin proteins, however, occur unpaired. Various epithelial cells contain different keratin proteins, in a tissue-specific manner. Antibodies to keratin proteins are widely used for histologic typing of tumors, and are especially useful for distinguishing carcinomas from sarcomas, lymphomas, and melanomas. Synonym(s): ceratin, cytokeratin [G. keras (kerat-), horn, + -in] keratin (kĕr′ə-tĭn)n.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.ker·a·tin (ker'ă-tin) A scleroprotein or albuminoid present in hair and nails; it contains a relatively large amount of sulfur, is insoluble in gastric juice, and is sometimes used for coating tablets that are intended to be dissolved only in the intestine.
Synonym(s): cytokeratin. [G. keras (kerat-), horn, + -in]keratin A hard protein (scleroprotein) of cylindrical, helical molecular form occurring in horny tissue such as hair and nails and in the outer layers of the skin. Hair and nails consist almost wholly of keratin. Keratins are insoluble and cannot generally be split by PROTEOLYTIC enzymes.keratin a hard, fibrous, sulphur-containing protein with an alpha-helix structure, found in the epidermis of vertebrates, mainly in the outermost layers of skin. Keratin can have several forms: in scales, feathers, hooves, horns, claws and nails it is hard, while wool and hair are made up of a soft and flexible form.KeratinA tough, nonwater-soluble protein found in the nails, hair, and the outermost layer of skin. Human hair is made up largely of keratin.Mentioned in: Epidermolysis Bullosa, Ichthyosis, Keratosis Pilarisker·a·tin (ker'ă-tin) Collective name for a group of proteins that form intermediate filaments in epithelial cells. Keratins have a molecular weight of 40-68 kD and are either acidic or basic. Antibodies to keratin proteins are widely used for histologic typing of tumors and are especially useful for distinguishing carcinomas from sarcomas, lymphomas, and melanomas. [G. keras (kerat-), horn, + -in]Patient discussion about keratinQ. skins does excrete oil and keratin what exactly is the whitish cape up that you can squeeze out from underskin A. It sounds like you refer to sebum, an oily substance secreted by (how surprising :) ) sebaceus glands attached to the hair root. It's important for the skin, although abnormal secretion of it may cause diseases such as acne.
You may read more here:
http://en.wikipedia.org/wiki/Sebum#Sebum
More discussions about keratinAcronymsSeeKRTkeratinenUK
Synonyms for keratinnoun a fibrous scleroprotein that occurs in the outer layer of the skin and in horny tissues such as hair, feathers, nails, and hoovesSynonymsRelated Words- feather
- plumage
- plume
- hair
- horn
- albuminoid
- scleroprotein
|