Description:
 Now, even far from biology people know that the human body needs vitamins C and E, and beta-carotene. Without these substances does not do any remedy for wrinkles, no one multivitamin complex. These substances, different in their chemical nature, one thing in common - they are antioxidants.
In addition to these conventional antioxidants in our lives include bioflavonoids, selenium, superoxide dismutase and other substances whose names now and then occur in the annotations of cosmetics and food supplements. Perhaps many have heard about free radicals and that what needed antioxidants.
However, the doctrine of free radicals is so important for understanding the mechanisms of aging that we must once again make out the main provisions. Everyone knows that oxygen is necessary for life, so everyone is afraid to oxygen starvation. In fact, you can not live without oxygen, and even a slight decrease in oxygen content in the air immediately reflected in our being. Yet it is dangerous to living beings.
Hazardous it makes the same properties that made it necessary. All aerobic creatures obtain energy by oxidizing organic molecules with oxygen. And they must be protected from the high oxidizing ability of oxygen. Indeed, the oxidation - is the same as burning. Just in the body substance "burn" gradually, in stages, releasing energy in small portions.
If organic molecules quickly burned as firewood in the oven, the cell would have died from heat shock. Once the molecule is oxidized, it changes. This is not the same molecule that was before. For example, wood pulp in the process of burning firewood is oxidized to carbon dioxide and water - turns up in smoke.
The reaction of oxidation can be imagined as taking away anything. For example, if you took away the purse on the street, you will be "oxidized". In this case the man who captured the purse, "recovered". In the case of the solute-oxidant takes electron from another substance and restored. Oxygen - a very strong oxidizer. Even more powerful oxidants are free radicals of oxygen.
Free radical - a molecule that has high reactivity, as it has space for the electron, which it seeks to take away from other molecules. When he does, the radical becomes inactive and out of the game, but devoid of an electron (oxidation) of the molecule once it becomes radical and takes the path of robbery.
The molecules that were previously inert and no one responded, now enter into the most bizarre chemical reactions. For example, two molecules of collagen, which become free radicals, faced with oxygen radicals, become so active that communicate with each other. Crosslinked collagen is less elastic than normal, so the accumulation of collagen dimers in skin leads to wrinkles.
In the DNA radicals can be even two parts of one DNA strand. Damage to the DNA molecules cause cell death or cancerous degeneration. No less dramatic ends meet free radical oxygen molecules, enzymes.
Damaged enzymes can no longer manage chemical transformations, and the cell chaos reigns. 31 Free oxygen radicals are often formed as by-products of biological oxidation, but they can occur as a result of external factors - such as ultraviolet radiation or ionizing radiation. The place of formation of free radicals in biological oxidation are mitochondria - the energy plant cells. And that mitochondria are particularly vulnerable to free radicals.
It is a vicious circle: the free radical damage to mitochondria leads to disruption of energy cells and increased production of free radicals. Advocates of the mitochondria from free radicals is vitamin E and coenzyme Q (ubiquinone). The rate of production of free radicals in mitochondria increases with overeating, when the body has to process more nutrients than it needs.
The most serious consequence of the appearance of free radicals in the cell is lipid peroxidation. Peroxide call it because its products are peroxide. The most common mechanism for peroxide oxidized unsaturated fatty acids that make up the membranes of living cells. Exactly how lipid peroxidation can go in oils, which contain unsaturated fatty acids, and then the oil rancid (lipid peroxides have a bitter taste). The risk of peroxidation in the fact that it proceeds by a chain mechanism, ie such oxidation products are not only free radicals, but also lipid peroxides, which are very easily converted into the new radicals.
Thus, the number of free radicals, and thus the rate of oxidation of an avalanche increases. Free radicals react with all biological molecules, which are found in their path, such as proteins, DNA, and lipids. If an avalanche of oxidation is not stopped, it can die the whole organism.
This is what happens to all living organisms in an oxygen environment, if nature had not taken care to provide them with a powerful system of protection - the antioxidant system. Antioxidants - are molecules that can block the reaction of free radical oxidation, restoring oxidized compounds. When the antioxidant gives its electron oxidant and interrupts its destructive march, he himself is oxidized and becomes inactive.
In order to return it in working condition it should be again restored. Therefore, antioxidants, as experienced operatives usually work in pairs or groups, in which they can support the oxidized companion and quickly restore it. For example, vitamin C regenerates vitamin E and glutathione regenerates vitamin C. The best antioxidant cooperatives contained in plants.
This plant polyphenols or bioflavonoids, which work together very effectively combat free radicals. The most powerful anti-oxidant systems have plants that can grow in harsh conditions - sea buckthorn, pine, cedar, fir, and others. An important role in the body play an antioxidant enzyme. This superoxide dismutase (SOD), catalase and glutationperoxydaze. SOD and catalase antioxidant form a pair, which fights free radicals of oxygen, giving them the opportunity to start a chain oxidation processes.
Glutationperoxydaze detoxifies lipid peroxides, thereby interrupting a chain lipid peroxidation. For glyutationperoksitazy need selenium. Therefore, dietary supplements with selenium increase the antioxidant protection of organism. Antioxidants in the body have many connections.
This tocopherols, carotenoids, ascorbic acid, antioxidant enzymes, female sex hormones, coenzyme Q, thiol compounds (containing sulfur), some amino acids and protein complexes, vitamin K and many others.
However, despite such powerful antioxidant protection, free radicals still have quite a devastating effect on biological tissue and, in particular, to the skin. The reason for this is a factor that boosts the production of free radicals in the body, which leads to overload the antioxidant system and oxidative stress. The most important of these factors is UV radiation.
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