Free radical reactions: formation of adducts with biomolecules and their biological significance

Inherent in oxygen utilization by aerobic organisms is the possibility of damage to biomolecules by oxidative reactions, a phenomenon that has come to be called oxidative stress. The most extensively studied deleterious reactions in biological systems have been free radical chain reactions which lead to degradation of biomolecules and cellular structures. As discussed in this review, however, elucidation of the mechanisms by which free radicals play their physiological and pathological roles may require a better understanding of the addition reactions between free radicals and biomolecules.