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The free radical theory of aging states that organisms age because cells accumulate free radical damage over time. [ 1 ] A free radical is any atom or molecule that has a single unpaired electron in an outer shell. [ 2 ] While a few free radicals such as melanin are not chemically reactive, most biologically relevant free radicals are highly ...
Biogerontology is the sub-field of gerontology concerned with the biological aging process, its evolutionary origins, and potential means to intervene in the process. The term "biogerontology" was coined by S. Rattan, and came in regular use with the start of the journal Biogerontology in 2000. It involves interdisciplinary research on the ...
Telomerase is a reverse transcriptaseenzymethat carries its own RNA molecule(e.g., with the sequence 3′-CCCAAUCCC-5′ in Trypanosoma brucei)[3]which is used as a template when it elongates telomeres. Telomerase is active in gametesand most cancercells, but is normally absent in most somatic cells. History.
Senescence (/ sɪˈnɛsəns /) 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 with increasing age, at least in the later part of an organism's life cycle. [ 1 ][ 2 ] However, the resulting effects of ...
DNA damage theory of aging. The DNA damage theory of aging proposes that aging is a consequence of unrepaired accumulation of naturally occurring DNA damage. Damage in this context is a DNA alteration that has an abnormal structure. Although both mitochondrial and nuclear DNA damage can contribute to aging, nuclear DNA is the main subject of ...
The hallmarks of aging are the types of biochemical changes that occur in all organisms that experience biological aging and lead to a progressive loss of physiological integrity, impaired function and, eventually, death. They were first listed in a landmark paper in 2013 [1] to conceptualize the essence of biological aging and its underlying ...
Un-repaired DNA damages accumulate in non-replicating cells, such as cells in the brains or muscles of adult mammals, and can cause aging. [3] [4] [5] (Also see DNA damage theory of aging.) In replicating cells, such as cells lining the colon, errors occur upon replication past damages in the template strand of DNA or during repair of DNA damages.
In 1968 it took the form and became known as the neuroendocrine theory of aging. [38] [39] [40] 1956 Denham Harman proposed the free-radical theory of aging and demonstrated that free radical reactions contribute to the degradation of biological systems. [41] The theory is based on the ideas of Rebeca Gerschman and her colleagues put forward in ...