Free radicals are incomplete, unstable molecules. These molecules are basic building blocks in nature, such as oxygen, fatty acids, and amino acids. Electrons hold molecules together. All the normal molecules have pairs of electrons.
The oxygen molecules have 4 pairs of electrons. Suppose the molecules loses one of its electrons. We now have a free radical. A free radical or oxidant particle is a molecule that for one reason or the other is missing one of its electrons. This makes it unbalanced and extremely reactive with other molecules. The free radical wants to replace its electron. It will now aggresively seek an electron by hijacking one from a second molecule. This hijacking is not a gentle theft. It is a violent mugging. The second molecule now needs an electron, so it will hijack a third and so on in a chain reaction. This free radical damage is often called oxidation. Each time this theft involves a normal cell, the molecules may be destroyed, and the cells will perhaps become unstable to function or even die.
Free radicals can easily bind to and attack fats, carbohydrates, protein, enzymes, and DNA. They can interfere with cells health function and reproduction. Not all free radicals are destructive. Our body needs them to function. You need free radicals to oxidize glucose and fat while your immune system uses free radicals to fight virus and bacteria.
To give a very visible example of free radical damage, take a look at sun damaged skin. Often there will be brown spots (lipofuscin) on the back of hans and wrists. Lipofuscin consists of molecules of damaged, useless cell components and oxidized fatty particles. This same lipofuscin you see on the skin is being deposited on and in various parts of the body such as heart, brain, eyes, and other internal organs as a result of various kinds of oxidant damage. Not a very healthy situation.
The most common free radicals:
The most common free radicals are built on oxygen molecules. Remember- free radicals and oxidants particles are synonymous. Now let’s take a look at these little cell destroyers.
Superoxide is usually the first free radical formed. It is our friend oxygen with electron troubles. It is the beginning of our damage, and most of the other’s spring from the superoxide radical. It is the most abundant and active free radical.
Hydrogen Peroxide is formed by the conversion of the superoxide radical. This molecule can pass through the cell membrane and harm the delicate parts inside the cell.
Hydroxil Radicals are the most dangerous of all the free radicals because it can directly attack DNA. They are formed when the superoxide and hydrogen peroxide react together. They are extremely reactive and will attack any molecule arund them.
 Dr. Bruce Miller DDS, CNS. Family Health “Complete guide to better health and longevity”. Antioxidants – What are free radicals. 2019.202-205.