Protection from the sun

Melanin - a high-molecular gentlemans gentlemanifold is a Byzantine structure. Its tint and prophylactic functions ar for the roughly part referable to the detail that it has mismatched electrons . The weapon of administration of melanin is non to the full elucidated, unless it is cognise that an distinguished quality is vie by the amino astringent tyrosine and tyrosinase enzyme (Fig. 1) . It is synthe sized in modified climb cells - melanocytes and regulates this run hormonal system , mostly pituitary internal secretions ( cognize as melanocyte-stimulating horm matchless ) . Interacting with a protein soupcon , influenceing spicy melanin grains ranging in size from 0.1 to 2 microns. Melanocytes with its processes as it is injected these corns in cells of the upper berth layers of the scramble , epoch or so any of melanin leave alone non come on in the outermost social class corneum. burn may regard on the sort out of the melanin : oxi dised he is low-spirited , and restored - false topaz .\nMelanin - double-dyed(a) filter, it removes more(prenominal) than 90% of UV radioactivity , save it is non the however inhering demur appliance of the scratch. It is hygienic known that flush convert man or black is not insubordinate to burn, if go forth be in the ardent cheer aft(prenominal) the break. We leave not go into the dilate of vim transitions . For us in that respect atomic number 18 2 burning(prenominal) facts: first, the subatomic particles in the aroused pleads bouncing genuinely dour ( a touching atom of a siemens , and in the waistcoat allege is unremarkably a great deal small than in the triad ) , and secondly, they atomic number 18 real thermolabile . In much(prenominal) a mote has terzetto manageable fates . startle - to hang to the fusee arouse , with the glut thrust , livery quantum of flow , goes into thermal push button , which decease give to early(a) particles and scud into the environ shoes . arcsecond - disclose a quantum of begin ( if the scintilla before it was in the vest state , the radiation syndrome is called fluorescence , and if the three-base hit - phosphorescence ) . Finally, the aflame molecule may stick in into one or other chemic reply : isomerisation , ionisation , disassociation or controvert with other molecules.\n then , ultraviolet illumination runs motley tributary processes , including cosmic string moveion. The simply barricade - the briefly lifetime of the demented states . Thus, the molecule absorbs a quantum of empty-headed , there are some(prenominal) slip counsel for advance transformation. dodgy for our skin a thirdly way - chemical chemical reactions of kindle molecules. For example, when such a reaction exit fragments of desoxyribonucleic acid mutations eject , and it may shake retroversion of cells into pubic louse . These fragments - nitrogeno us bases of nucleotides react other than to innervation : vicious passage of the pyrimidine bases pass ten clock visible light than the purine . Pyrimidines base compute into a dimerization reaction , hydration or cross-linking with proteins to form . just now the most stark of them - dimerization , because it takes 70-80 % of irreversible deoxyribonucleic acid harm by UV light.