Collagen/ja: Difference between revisions

[[Ehlers–Danlos syndrome]] – Thirteen different types of this disorder, which lead to deformities in connective tissue, are known. Some of the rarer types can be lethal, leading to the rupture of arteries. Each syndrome is caused by a different mutation. For example, the vascular type (vEDS) of this disorder is caused by a mutation in ''collagen type 3''.

[[Alport syndrome]] – Can be passed on genetically, usually as X-linked dominant, but also as both an autosomal dominant and autosomal recessive disorder, those with the condition have problems with their kidneys and eyes, loss of hearing can also develop during the childhood or adolescent years.

[[Knobloch syndrome]] – Caused by a mutation in the [[COL18A1]] gene that codes for the production of collagen XVIII. Patients present with protrusion of the brain tissue and degeneration of the retina; an individual who has family members with the disorder is at an increased risk of developing it themselves since there is a hereditary link.

==Characteristics==

Collagen is one of the long, [[fibrous protein|fibrous structural proteins]] whose functions are quite different from those of [[globular protein]]s, such as [[enzyme]]s. Tough bundles of collagen called ''collagen fibers'' are a major component of the [[extracellular matrix]] that supports most tissues and gives cells structure from the outside, but collagen is also found inside certain cells. Collagen has great [[tensile strength]], and is the main component of [[fascia]], [[cartilage]], [[ligament]]s, [[tendon]]s, [[bone]] and skin. Along with [[elastin]] and soft [[keratin]], it is responsible for skin strength and elasticity, and its degradation leads to [[wrinkle]]s that accompany [[aging]]. It strengthens [[blood vessel]]s and plays a role in [[biological tissue|tissue]] development. It is present in the [[cornea]] and lens of the eye in [[crystal]]line form. It may be one of the most abundant proteins in the fossil record, given that it appears to fossilize frequently, even in bones from the [[Mesozoic]] and [[Paleozoic]].

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===Uses===

[[file:Beretta Salami and Collagen Casing .jpg|right|150px|thumb|A salami and the collagen casing (below) it came in]]

Collagen has a wide variety of applications, from food to medical. In the medical industry, it is used in [[plastic surgery|cosmetic surgery]] and [[burn (injury)|burn surgery]]. In the food sector, one use example is in [[casing (sausage)|casings for sausages]].

If collagen is subject to sufficient [[denaturation (biochemistry)|denaturation]], such as by heating, the three tropocollagen strands separate partially or completely into globular domains, containing a different secondary structure to the normal collagen polyproline II (PPII) of [[random coil]]s. This process describes the formation of [[gelatin]], which is used in many foods, including flavored [[gelatin dessert]]s. Besides food, gelatin has been used in pharmaceutical, cosmetic, and photography industries. It is also used as a [[dietary supplement]], and has been advertised as a potential remedy against the ageing process.

From the Greek for glue, ''kolla'', the word collagen means "[[animal glue|glue]] producer" and refers to the early process of boiling the skin and [[tendon|sinews]] of horses and other animals to obtain glue. Collagen adhesive was used by Egyptians about 4,000 years ago, and Native Americans used it in [[bow (weapon)|bows]] about 1,500 years ago. The oldest glue in the world, [[radiocarbon dating|carbon-dated]] as more than 8,000 years old, was found to be collagen – used as a protective lining on rope baskets and [[embroidery|embroidered]] [[Textile|fabric]]s, to hold [[list of eating utensils|utensils]] together, and in crisscross decorations on [[human skull]]s. Collagen normally converts to gelatin, but survived due to dry conditions. Animal glues are [[thermoplastic]], softening again upon reheating, so they are still used in making [[musical instrument]]s such as fine violins and guitars, which may have to be reopened for repairs – an application incompatible with tough, [[chemical synthesis|synthetic]] plastic adhesives, which are permanent. Animal sinews and skins, including leather, have been used to make useful articles for millennia.

Gelatin-[[resorcinol]]-[[formaldehyde]] glue (and with formaldehyde replaced by less-toxic pentanedial and [[glyoxal|ethanedial]]) has been used to repair experimental incisions in rabbit [[lung]]s.