Answer:
Free radical theory of aging.
Explanation:
Free radical theory of aging suggests that aging is the result of unstable oxygen molecules that cause damage to the structure of cells with age because cells accumulate free radical damage overtime and free radical is an atom with unpaired electron in it's outermost shell. It is associated with oxidative damage.
the free radical theory is only concerned with free radicals such as superoxide ( O2− ), but it also comprises of oxidative damage from other reactive oxygen species such as hydrogen peroxide (H2O2), or peroxynitrite (OONO−).