Health / Medical Topics |
Free radical
Pronunciation
Definition 1
A type of unstable molecule that is made during normal cell metabolism (chemical changes that take place in a cell). Free radicals can build up in cells and cause damage to other molecules, such as DNA, lipids, and proteins. This damage may increase the risk of cancer and other diseases. (NCI Dictionary)
Definition 2
Molecules or atoms with at least one unpaired or 'free' electron in the outermost electron shell. Chemically unstable, free radicals stabilize themselves by appropriating an electron from a nearby molecule, thereby damaging that molecule by altering the electron number in its outermost electron shell. By-products of both normal cell processes and environmental toxin exposure, oxygen free-radicals in high concentrations may damage DNA, proteins, and lipids, thereby increasing the risk for various diseases including cancer. (NCI Thesaurus)