stiner- aging Flashcards
hayflick limit
Differentiated cells from animals undergo only a limited number of cell divisions (population doublings) in tissue culture, unless they become transformed to cancer cells by mutation or infection with certain viruses
two theories of again
Biological – Genetically controlled event
Chemical – Somatic, cumulative chemical damage to biomolecules
biological aging
Determined by the programmed expression or repression of genetic information.
Longer-lived species have more efficient
DNA repair processes
Biologic theories attribute differences in lifespan to interspecies differences in _______but also provide an explanation for the observation that there is a ________ to longevity within a species
genetics ,genetic component
EFFICIENCY OF DNA REPAIR MECHANISMS ARE CLOSELY CORRELATED what?
TO LIFESPAN.
The most widely accepted chemical theory of aging is what?
free radical theory of aging (FRTA).
Aging results from cumulative what?
oxidative damage to biomolecules: DNA, RNA, protein, lipids, and glycoconjugates.
Longer-lived organisms have lower rates of production of ____, better _______, and more efficient repair or turnover processes.
ROS, antioxidant defenses
what is the only intervention that consistently extends maximum lifespan in a variety of species, including mammals, fish, flies, worms, and yeast.
Calorie restriction (CR)
___________ during CR, rather than the decrease in food consumption, appears to have the greater effect on lifespan extension.
the decrease in body weight or adiposity
