biochemical changes which cause ageing

[1aztarot2]

what are the main biochemical changes which occur which cause ageing? i have heard of free radicals but i was wondering if there were any other factors which are thought to cause the ageing process.

[zhangyuzhi]

misfolded proteins?

[Reaver]

Free radicals are one part - they cause DNA damage.

Exposure to ultraviolet light also causes DNA damage and so causes ageing.

The other issue is with telomeres, which are basically protective "caps" on the ends of the chromosomes. Every time a cell replicates, a small part of the telomeres is cut off. When you get towards old age, the telomeres wear out and you start damaging the DNA instead.

Interestingly, cancer cells are able to maintain their DNA using an enzyme called telomerase, which repairs the telomeres. Telomerase is present normally, but is limited to areas which need to undergo cell division very regularly (e.g. stem cells, immune cells, etc).

Hope this helps.

[Anna L]

active forms of oxygen affect ageing also