Cell ageing

What are the theories of aging?

Genetic-Cells are programmed to die at certain age,

Wear and tear-organism needs to balance between energy for reproduction and energy for maintenance (blocking reproduction can allow for longer lifespan)

Environment-Environmental factors may accelerate ageing (foetal programming)

Disposable soma theory-force of natural selection decreases at age, and genes that benefit earlier may be determinate later, trade off between reproduction/maintenance

What is the stochastic theory of ageing?

random events at cellular/molecular levels cause ageing

What are three examples of aging processes?

Senescence-programmed cell death

oxidative stress-DNA repair and protein damage

gene expression-accurate DNA replication, protein synthesis

What is cell senescence?

Cells can only replicate a certain amount-hayflick limit

due to telomeres which shorten every cell division, eventually too short and cell prevents proliferation

some cells have telomerase which maintains length (cancers have)

What are involved in oxidative stress?

calorific restriction prolongs lifespan

free radical production (ROS) damage cellular components UV/radiation

antioxidants