On a biological level, free radicals are oxygen-containing moleculas that have an impaired electron. For example, superoxide ( O2-) and some other reactive oxygen species (e.g. OH-) are free radicals. Our cells produce thousands of free radicals every day through a process of oxidation in the body. Oxidation is an essential process in our bodies that generates energy, but it is also damaging one because of free radicals reactivity. Since free radicals have at least one unpaired electron, they are unstable. In other words, their atoms are not in a ground state. The presence of unpaired electrons make free radicals highly reactive. To become stabilised or “ground” the free radical must obtain an electron from another molecular. When free radicals steal an electron from a surrounding molecule a new free radical is formed in its place. The newly formed radical then looks to return to its ground state by stealing electrons from cellular structures or molecules. Thus the chain reaction (of atoms stealing electrons) continues and can be thousands of events long.
Sources of Free Radicals:
|Internally generated sources:||Externally generated sources:|
|-oxidation during exercise
-reactions involving iron and -other transition metals
-certain drugs, pesticides,
-anaesthetics and industrial solvents