Reaction principle:
We know that cells get oxygen by breathing, 98% of which is combined with glucose and fat in organelles and converted into energy to meet the needs of cell activities, and the other 2% is converted into oxygen free radicals. Because this substance is very active, it can almost interact with all kinds of substances, causing a series of destructive chain reactions to cells. Under normal circumstances, cells will not be killed by this molecular killer. This is because there are a lot of antioxidants in our human cells, such as fat-soluble vitamin E, water-soluble vitamin C and some enzymes. These natural antioxidants can undergo redox reaction with oxygen free radicals, thus completely eliminating oxygen free radicals. Only in some cases, oxygen free radicals can kill cells and even the body.
Harm to human body:
When the human body is hit hard by trauma, poisoning or major surgery bleeding, the tissue is in a state of hypoxia, energy metabolism is blocked, cytochrome oxidase can't reduce oxygen to water, oxygen atoms will be deprived of an electron, and harmless oxygen will become deadly active oxygen free radicals. The peroxide killing of oxygen free radicals is mainly to destroy the structure and function of cell membrane and mitochondria, cut off the energy of cells, destroy lysosomes and make cells autolyse. At the same time, it also has adverse effects on the non-cellular structure of human body, which can destroy the adhesive on the blood vessel wall, make the intact sealed blood vessel riddled with holes, leak blood and exudate, and then lead to edema and purpura. Similarly, when the coronary artery supplying heart blood suddenly spasms, myocardial cells undergo a series of metabolic changes due to hypoxia, and the content of antioxidants in myocardial cells decreases, which makes the chemical reaction of producing oxygen free radicals relatively accelerated due to hypoxia. At the moment of coronary artery spasm resection, myocardial cells suddenly get blood perfusion again, which is followed by a large amount of oxygen converted into oxygen free radicals. At the same time, due to the relative shortage of antioxidants, oxygen free radicals cannot be removed. As a result, highly lethal oxygen free radicals seriously damage myocardial cell membrane, and a large number of ions overflow from myocardial cells, which can disturb the current signal controlling heartbeat, cause ventricular fibrillation and lead to death.
cause
So why do oxygen free radicals age the human body? In recent years, it has been found that oxygen free radicals are very active in chemistry and can attack fatty acids on cell membranes to produce peroxides. These substances are very toxic, which will infringe on the nucleic acid and protein in the body and cause a series of cell destruction. The more oxygen free radicals accumulated in the human body, the faster the aging process will be. Our common spots on the faces of the elderly are all caused by the oxidative decomposition of lipids to form malondialdehyde. Oxygen free radicals are not only related to aging, but also to many diseases related to aging, such as arteriosclerosis, hypertension, osteoarthritis, cataract, Parkinson's disease and so on.
Coping method
As for the methods to deal with oxygen free radicals, many bane of oxygen free radicals, namely oxygen free radical scavengers or inhibitors, have been found. Some of their mechanisms are to directly provide electrons to reduce oxygen free radicals, and some are to enhance the activity of antioxidant enzymes and quickly remove free radicals. For example, superoxide dismutase (SOD) and catalase (CAT) are important enzyme systems for scavenging oxygen free radicals in normal human tissues. In addition, glutathione, allopurinol, vitamins C and E all have the effects of scavenging or inhibiting oxygen free radicals.
Edit this paragraph and find that
According to the study of nutritional epidemiology, eating fresh vegetables and fruits regularly can delay aging and reduce the incidence of tumors, especially digestive tract tumors. It is because vegetables can remove the main precursor product of oxygen free radicals, that is, superoxide anion. When the superoxide anion decreases, the oxygen free radicals will also decrease correspondingly, which can also delay the aging of human body. Nutritionists have found that most fruits and vegetables have the activity of scavenging superoxide anion, among which shepherd's purse, green vegetables, garlic and soybean sprouts have the strongest scavenging ability. In addition, you often eat cauliflower, carrot, spinach and sweet potato rich in vitamin A, grapes, oranges and green peppers rich in vitamin C, lemons, peas, unprocessed wheat germ, sunflower seed oil and vitamin E, etc.