Free Radicals Definition

A fee radical is termed to the molecular kinds which can contain an unpaired electron in their atomic orbital and can exist independently. All the radicals share some of the common properties due to the unpaired electron.

Properties of Free Radicals

  • These radicals are highly reactive and very unstable
  • They can donate an electron or accept an electron from other molecules, therefore, can behave as oxidants or reactants.

Examples of Free Radicals

  • The most important free radical which consists of oxygen are hydroxyl radical
  • Superoxide anion radical
  • Hydrogen peroxide
  • Hypochlorite
  • Nitric oxide radical
  • Peroxyntrite radical

Uses of Free Radicals

  • These highly reactive structures are present in the membranes of cells of damaging biologically relevant molecules such as the DNA, lipids, proteins, and carbohydrates etc.
  • The free radicals attack important macromolecules which leads to cell damage and homeostatic disruption such as proteins, nucleic acids etc.

Sources of Free Radicals

Free radicals are generated internally through this following sources.

  • Mitochondria
  • Inflammation
  • Exercise
  • Phagocytosis
  • Peroxisomes

Free radicals are found externally in the following sources.

  • Environmental pollution
  • Cigarette smoke
  • Radiation
  • Drugs and pesticides
  • Ozone layer