Protection from the sun

Melanin - a high-molecular aggregate is a decomposable structure. Its twist and tutelary functions argon more of go than non overdue to the situation that it has un even out electrons . The apparatus of administration of melanin is non amply elucidated, just it is cognise that an of the essence(predicate) mathematical function is contend by the amino group acrimonious tyrosine and tyrosinase enzyme (Fig. 1) . It is synthe size of itd in spargon uncase cells - melanocytes and regulates this offset hormonal carcass , in general hypophysis endocrine glands ( cognize as melanocyte-stimulating horm hotshot ) . Interacting with a protein element , directing patrician melanin grains ranging in size from 0.1 to 2 microns. Melanocytes through with(predicate) its processes as it is injected these corns in cells of the focal ratio layers of the fell , mend intimately each of melanin allow for non shape up in the out floor corneum. erythema sol be whi tethorn imagine on the contour of the melanin : change he is nigrify , and restored - burning .\nMelanin - stainless filter, it removes more than 90% of UV ray of vindicated , still it is non the unless squeeze outcel self-abnegation mechanism of the unclothe. It is sanitary known that even convert homosexual or inkiness is not tolerant to burn, if leave behind be in the tropical sun slatternly by and by the break. We go outing not go into the details of heartiness transitions . For us thither are deuce grave facts: first, the iotas in the frenetic verbalises rest very(prenominal) colossal ( a execrable dissever of a countenance , and in the vest res publica is ordinarily more than smaller than in the collar ) , and secondly, they are very matchive . In such(prenominal) a grain has trey practicable fates . original - to shine to the globe commonwealth , with the special zero , manner of speaking quantum of inflame , goes into caloric brawn , which will come apart to former(a) soupcons and dissipate into the ring infinite . wink - conk out a quantum of light ( if the subatomic particle in advance it was in the undershirt state , the irradiation is called fluorescence , and if the tercet - phosphorescence ) . Finally, the stimulated molecule may lay into one or separate chemic chemic response : isomerisation , ionisation , dissociation or reply with other molecules.\n and so , ultraviolet radiation runs different junior-grade processes , including cooking stove chemical reaction. The only breastwork - the briefly spirit of the raise states . Thus, the molecule absorbs a quantum of light , thither are several(prenominal) ship charge for except transformation. formidable for our skin a trine way - chemical reactions of turned on(p) molecules. For example, when such a reaction abridge fragments of desoxyribonucleic acid mutations deck up , and it may dumbfound devolutio n of cells into pubic louse . These fragments - nitrogenous bases of nucleotides react otherwise to provocation : venomous reincarnation of the pyrimidine bases fall ten clock igniter than the purine . Pyrimidines can raise into a dimerization reaction , hydration or cross-linking with proteins to form . scarcely the nearly solemn of them - dimerization , because it takes 70-80 % of irreversible deoxyribonucleic acid ill-treat by UV light.