keratin

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Related to keratinous: keratinous cyst

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.
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 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.
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, 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.
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. 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
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 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.

keratin

A 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.
References in periodicals archive ?
deep invagination of epidermis that is filled with keratinous material and invagination not related to hair follicle are consistent with the diagnosis of NC.
Microscopy: Keratinous debritic material along with a nucleate squamous s/o Keratinous cyst.
There may be drainage of malodorous keratinous and purulent debris.
10,300,002 B2 (Konstantin Goutsis, Gabriele Weser); Henkel AG & Co., Duesseldorf, has patented a composition for dyeing keratinous fibers.
YDs in AA are keratinous and in AGA, represent sebaceous debris.
Otoscopic examination of the left ear revealed impacted wax with keratinous debris in the EAC.
In this circumstance, only viable tumor--not necrotic keratinous debris or keratin granulomas--should be categorized as a positive lymph node (Figure 3).
The Bureau of Fisheries and Aquatic Resources (BFAR) conducted tests on a sample of "galunggong" (round scad) and found out that a "keratinous layer" was covering it and not plastic as earlier believed by those who saw it from a video uploaded on Facebook over the weekend.
Microbial KEs are predominantly extracellular when grow on keratinous substrates and can be stable over a wide range of pH from 5 to 13 [31].
In Pakistan, Poultry industries are ranked among the most important sectors contributing economically owing to the enormous consumption of chicken meat; on the other hand, it causes the accumulation of huge quantities of keratinous waste because of poor solid waste management strategies.
These represent distension of affected follicular infundibulum with keratinous material and sebum.5 Ross et al.5 demonstrated yellow dots in 94.8% patients.
(2010) reported the rupture of the tick cuticle due to the penetration of the IJs using this keratinous tooth; even when Samish et al.