What is Free radical?
A '''free radical''' is an [[atom]] or [[molecule]] with an unpaired [[electron]]. The radical is reactive and seeks another electron to pair.<ref name=Rice-Evans1> Rice-Evans, C. (1999). “Screening of phenolics and flavonoids for antioxidant activity”. In: Antioxidant Food Supplements in Human Health. Academic Press, p. 239–253. </ref> Free radicals are involved in the causes of damage associated with disease development. Examples are hydrogen peroxide, hypochlorite, nitric oxide and nitrogen dioxide.<ref name=AfzalArmstrong1> Afzal, M., Armstrong, D. (2002). “Fractionation of herbal medicine for identifying antioxidant activity”. In: Armstrong, D. (Ed.) Methods in Molecular Biology, vol. 186: Oxidative Stress Biomarkers and Antioxidant Protocols, Humana Press Inc. </ref> The need for [[Antioxidant|antioxidants]] in people's daily lives is becoming more critical with increased exposure to free radicals. [[Oxygen]] is highly reactive and can form free radicals; antioxidants can stabilize or deactivate oxygen free radicals before they attack [[Cell|cells]]. Pollution, cigarette smoke, drugs, illness, and stress can increase our exposure to oxygen free radicals.<ref>Percival, M. (1998). “Antioxidants”. ''Clinical Nutrition Insights'' 1/96 Rev. 10/98. http://acudoc.com/Antioxidants.PDF</ref> == References == {{reflist}} [[Category:Chemistry]] {{science-stub}}