Search results
Results from the WOW.Com Content Network
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 ...
The mitochondrial free radical theory of ageing (MFRTA) proposes that free radicals produced by mitochondrial activity damage cellular components, leading to ageing. Free radicals damage mitochondria, which, according to the mitochondrial free radical theory of ageing, leads to ageing.
The species with longer lifespans were found to have slower accumulation of DNA damage, a finding consistent with the DNA damage theory of aging. [119] In healthy humans after age 50, endogenous DNA single- and double-strand breaks increase linearly, and other forms of DNA damage also increase with age in blood mononuclear cells. [ 120 ]
Stochastic theories of aging are theories suggesting that aging is caused by small changes in the body over time and the body's failure to restore the system and mend the damages to the body. Cells and tissues are injured due to the accumulation of damage over time resulting in the diminished functioning of organs.
The somatic mutation theory of ageing states that accumulation of mutations in somatic cells is the primary cause of aging. A comparison of somatic mutation rate across several mammal species found that the total number of accumulated mutations at the end of lifespan was roughly equal across a broad range of lifespans. [ 16 ]
Cross-links. Crosslinking of DNA; Free radicals – atom, molecule, or ion that has unpaired valence electrons. With some exceptions, these unpaired electrons make free radicals highly chemically reactive towards other substances, or even towards themselves: their molecules will often spontaneously dimerize or polymerize if they come in contact with each other.
There are numerous studies that support cellular damage, often due to a lack of somatic maintenance mechanisms, as a primary determinant for aging, and these studies have given rise to the free radical theory of aging and the DNA damage theory of aging. One study found that the cells of short-living rodents in vitro show much greater mutation ...
The network theory of aging provides a deeper look at the damage and repair processes at the cellular level and the ever changing balance between those processes. To fully understand the network theory as its applied to aging you must look at the different hierarchical elements of the theory as it pertains to aging.