Oxygen free radicals – formation, reactions and significance in the organism

Oxygen free radicals are obligatory side product of the aerobic cell metabolism. In the first part of the paper their main characteristics and formation paths as well as the reactions they trigger in the biological systems are described. The second part deals with some common cell injuries caused by free radicals or their metabolites. The last part discusses the organism’s defense mechanisms. Explanation of some abbreviations is added at the end.