The science behind the process of dying.

DNA Decay.
What? My DNA can decay? Could be. At least, both I and my neurobiology professor think so.

In a perfect world, when a person is born, they have nice long, healthy chromosomes that make up who they are. As they live, even if they're healthy and don't do drugs and things like that, mutations occur. Nonspecific mutations, but mutations. These mutations can cause different things to happen to your cells, but more importantly their DNA, ribosomes, and m/t/etcRNA.

For instance, a person with constant exposure to higher amounts of radiation than normal would be expected to have a shorter life. But why? They might never get radiation poisoning, or exhibit symptoms, but generally speaking, they're gonna die faster than someone who hasn't, even if the radiation levels were minute. This is because of chromosome mutation. It even happens naturally, and scientists are working on inhibitors to prevent this.

The consensus is that the mutations on chromosomes cause them to shorten, and one can even predict their lifespan based on this factor. When a chromosome shortens, the sequences it stores change. Proteins are produced differently, and your overall genetic makeup changes over time. (Gray hair?)

Just thought I'd bring an interesting topic to an interesting forum, anyone else have speculations or research journals to commit?

 

Is this just your speculation? Or is there an actual study that can substantiate this?

 

http://www.radiation-scott.org/radsource/3-0.htm

Edit: Sorry, should've clarified instead of just posting the link: that website contains pretty much every bit of information on why radiation exposure in high doses is dangerous and shortens life span.

 

So would extensive exposure to the sun make your life shorter? If so then in certain areas where the sun is hotter aka deserts or areas where the altitude is higher we should see shorter life spans?

sun exposure = radiation in case anyone didn't know that

 

The temperature is only weakly related to actual harmful radiation levels from the sun. Most of the heat from the sun is infrared light (i.e., light that is a higher wavelength/slower frequency than visible light), whereas the harmful rays are those that have shorter wavelengths/higher frequencies, like ultraviolet light. It can be cold outside and your body can still get pummeled by UV radiation. UV radiation is primarily blocked by the ozone layer, so regions with a lot of CFC and other pollution are at higher risk of UV radiation damage, whereas some deserts are actually relatively harmless because most industrialization occurs in temperate regions.

 

Did not realize that so would altitude have any affect on the amount of harmfull radiation you would receive?

 

Just a suggestion based on my education;
Shoudn't the title be somewhat like the following?
'The science behind the process of ageing'???
If you require a biochemical explanation - i would be able to easily provide it.

 

Ummm not to seem arrogant or anything, but it is quite scientifically accepted already that DNA does decay (or more correctly, 'denatures') over repetitive mRNA transcription and replications. Through each replication, the denatured segments of DNA are further 'inherited', if you like, into the newly created strands. Thus slowly all DNA (with a few exceptions, of course) will become less and less useful ('junk' DNA, if you will); and thus losing the ability to transcribe proteins, polypeptides; thus genes and genetic funtions. This is the largely accepted view of ageing.
The only way DNA change can directly result in death is through destructive mutation of multiple code sections (through entire phase translations of code)
that targets a vital gene; rendering it counterproductive or useless. This, or through the alteration of protein production genes (or transcription factors) which could induce proliferation of certain cells (more or less known to us as cancer)

 

after every amplification of DNA it becomes a slightly bit shorter on both ends.
when your young those ends of the DNA are protected by telomerase. scientists recently discovered they can add telomerase to rats(not tested on humans yet). what happened was that the rats started growing brain cells and nerve cells again.
so what they could do theoretically is making itpossible to let humans live for nearly eternity.
one slight problem tho... by the time you'd be 160 pretty much everyone woulda died from cancer.

what's your opinion on this? should this threatment become possible?

 

The initiating and terminal ends of DNA are protected by telomeres, just to add. Telomerase is the enzyme that catalyses the production of these bits of DNA.

And you're perfectly right. It's this unrestrictive growth property which is the foundation of cancerous growths.

 

Strong radiation is dangerous because of the fact that it can cause a double strand break, not so much due to the danger of a mutation.

Mutations in junk DNA don't do any damage, and about 1/3 of our genome is junk DNA, if I remember correctly.

 

98% of your dna is junk. only 2 percent of your dna codes for everything

 

Just reinforces my point, lol.

Strand break will halt any transcription or translation which was going on, and so it can lead to the death of the cell even faster than a cancer or mutation can.
Additionally, it's more likely to affect the cell because about 80% of DNA is translated or transcribed at some point. Mutations are only really dangerous when the amino acids they code for are assembled into proteins and the protein fails to function correctly.

 

Btw, cancer does not cause cell death. Cancer is the malignant proliferation of cells, which is quite the contrary.
Also, 100% of DNA is translated at some point. However, less than 3% is successfully transcribed.
Mutations are only dangerous when all of the following requirements are met:
- The mutation is a frameshift mutation OR it occurs in an important section of the resultant polypeptide's active site (assuming it has enzymal properties).
- The resultant polypeptide's shape is drastically malformed.
- The malformation prevents correct catalysis of substrate items.
- The catalysis of these subtrate items is vital for the development of a cell.

Unless ALL of these happen to be true, mutations are not dangerous to a cell.

 

Thanks for sharing intersting to read new things.