Free radical, also called "free radical" in chemistry, is an atomic group containing unpaired electrons. Because when atoms form molecules, electrons in chemical bonds must appear in pairs, so free radicals take an electron from other substances everywhere and make themselves form stable substances. In chemistry, this phenomenon is called "oxidation". Our biological system mainly encounters oxygen free radicals, such as superoxide anion free radicals, hydroxyl free radicals, lipid oxygen free radicals, nitrogen dioxide, nitric oxide free radicals and so on. Together with hydrogen peroxide, singlet oxygen and ozone, it is called active oxygen. Active oxygen free radicals in the body have certain functions, such as immunity and signal transduction. However, excessive reactive oxygen species will destroy normal cells and tissues of human body, thus causing many diseases. Such as heart disease, Alzheimer's disease, Parkinson's disease and tumor. In addition, solar radiation, air pollution, smoking, pesticides, etc. In the external environment, the human body will produce more reactive oxygen radicals and mutated nucleic acids, which is the root cause of human aging and illness.
Simply put, our world of atoms has a special law, that is, as long as more than two atoms are combined, their peripheral electrons must be paired. If there is no pairing, they will look for another electron and turn themselves into a stable element. Scientists call this atom or molecule with unpaired electrons a free radical.
When the original structure of a stable atom is broken by external force, resulting in the lack of an electron in this atom, free radicals are produced. So it will immediately look for the other half that can be combined with itself. It is very active and easily reacts with other substances.
When it gains or loses an electron in the process of combining with other substances, it will regain its balance and become a stable structure. This kind of electronic gain and loss activity may be beneficial or harmful to human beings.
Generally speaking, life is inseparable from free radical activities. Our bodies are moving from the inside out all the time, burning energy all the time, and the porter responsible for transmitting energy is free radicals. When these free radicals that help energy conversion are enclosed in cells and cannot run around, they are harmless to life. However, if the activity of free radicals is out of control and exceeds a certain amount, the normal life order will be destroyed and diseases may follow.
So free radicals are a double-edged sword. It is necessary for health to understand free radicals and their effects on human body.