what is the science of getting old ?

Question

i've searched for answers..
and mostly said.. about 'cells getting deteriorate'.
then why cells deteriorate ?
is there any connection with gravity ?
if there's no gravity, cells won't deteriorate ?
or any other factors ?
thanks

Answer 1

The science of getting old is called Gerontology.

And it is indeed about cells deteriorating. The major reason for this is successive errors in DNA replication over time.
An excellent analogy that was used on Yahoo Answers recently was that copying DNA is like copying a cassette/tape - it works pretty well, but over time, the quality will deteriorate. Basically, your DNA replication machinery is pretty good (this is actually called "High Fidelity"), but it is not 100%, so mistakes do creep in.

In the best case, these mistakes just lead to proteins in the cells not doing their job as well any more (so the cells don't function as well).
In the worst case, the errors lead to cancerous transformation of the cell - causing a cancer (when the cell "forgets" how to regulate its growth, and divides in an uncontrolled manner).

One major reason for the deterioration of your DNA is the shortening of the telomeres. Each of the ends of your chromosomes has a region called a telomere, which is non-coding DNA (it doesn't make any proteins). Every time your cells divide, the telomeres get a little shorter (this just a consequence of the way that DNA replication works at the ends of the chromosomes). Eventually, after enough divisions, the telomeres are "used up", and this shortening starts to "eat into" portions of your DNA that *do* make proteins. So these genes will therefore have large errors in them that get worse over time.

Gravity does not have any direct effects on ageing, but low gravity *will* mean that the heart is under less strain to pump blood around the body, so it might ease difficulties with that. Unfortunately, it has detrimental effects too, such as wasting away of the bones.

Interestingly, the DNA replication machinery in your germ-line cells (sperm and ova) is in fact *much* better than that of your body's cells ("somatic cells"), so serious DNA errors tend not to be transmitted to your children, unless they were already a genetic trait in your DNA (which would therefore not be recognised as a mistake during DNA replication).
The germ-line cells have an active enzyme called telomerase, which repairs the shortened telomeres, and stops that deterioration.
Unfortunately, active telomerase in somatic cells tends to be an indication of the aforementioned cancerous transformation.

Answer 2

It is not a gravity thing. It's mainly about damage to the DNA over a succession of replications.

Answer 3

If there is no gravity your muscles start to atrophy, this is why astronauts have to exercise constantly during their missions.

Answer 4

in my case..... cursing islam is the science that im gettin older day by day.