A free radical is a molecule or element with an unpaired electron.
Any molecule can become a free radical by either losing or gaining an electron.
Molecules containing these uncoupled electrons are highly reactive. Once initiated, free radicals become involved in chain reactions that damage the lipid membrane of cells. Free radicals play an important role , both in health and disease. Free radicals have been implicated in countless human disease processes, but according to a growing body of scientific literature free radicals are also vital to metabolic processes . Free radicals are produced in biological systems in a number of ways .