Skip to main content
Select Source:

free radicals

free radicals A free radical is any chemical species which contains one or more unpaired electrons and which is capable of an independent existence. An unpaired electron is one that can alone occupy an atomic or molecular orbital, conventionally denoted by a superscript dot: X.

The biologically important free radicals are the oxygen species, superoxide O2-, the hydroxyl radical OH, and the reactive nitrogen species NO; each may play a significant physiological or pathophysiological role in the body.

See ageing; nitric oxide; oxygen.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"free radicals." The Oxford Companion to the Body. . Encyclopedia.com. 11 Dec. 2017 <http://www.encyclopedia.com>.

"free radicals." The Oxford Companion to the Body. . Encyclopedia.com. (December 11, 2017). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/free-radicals

"free radicals." The Oxford Companion to the Body. . Retrieved December 11, 2017 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/free-radicals

free radicals

free radicals Highly reactive molecules with an unpaired electron. See antioxidant nutrients.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"free radicals." A Dictionary of Food and Nutrition. . Encyclopedia.com. 11 Dec. 2017 <http://www.encyclopedia.com>.

"free radicals." A Dictionary of Food and Nutrition. . Encyclopedia.com. (December 11, 2017). http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/free-radicals

"free radicals." A Dictionary of Food and Nutrition. . Retrieved December 11, 2017 from Encyclopedia.com: http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/free-radicals