Dr. Denham Harman, a professor emeritus at the University of Nebraska, is considered the father of a theory of aging in which they are key.  
Photolysis or pyrolysis in which a bond is broken without forming ions can produce these by-products of normal metabolism, which play a valuable role in fighting infection.  Dr. Denham Harman, a professor emeritus at the University of Nebraska, is considered the father of a theory of aging in which they are key.  Their namesake reactions involve covalent single bond changes in which one electron comes from each reactant.  FTP, name these molecules with at least one unpaired valence electron, and thus an electrical charge, which can damage cell membranes and cause DNA mutations.
Photolysis or pyrolysis in which a bond is broken without forming ions can produce these by-products of normal metabolism, which play a valuable role in fighting infection.  
free radicals