Free-radical theory of aging
Videos
The free radical theory of aging states that organisms age because cells accumulate free radical damage over time. A free radical is any atom or molecule that has a single unpaired electron in an oute
In chemistry, a free radical is any atom, molecule or ion with an unpaired valence electron.
Major sources of reactive oxygen species in living systems
Senescence
Videos
Senescence or biological aging is the gradual deterioration of functional characteristics in living organisms. Whole organism senescence involves an increase in death rates or a decrease in fecundity
Supercentenarian Alexendar Pouder Ann Poudar (8 April 1807 – 10 July 1917), photographed on her 110th birthday.
Elderly Klamath woman photographed by Edward S. Curtis in 1924