telomerase

[bigTOOTHguy]

can anyone do a good job of explaining telomerase to me. I know it extends with random repeating DNA segments, but then I am confused how they eventually shorten on the lagging strand. I accept this as a fact of biology, but I do not entirely understand the phenomenon.

 

[LazyP]

This is how I understood it to be... not all of the nucleotides are replicated at the end of the chromosome, thus telomerase adds telomere (repeating nucleotides which code for essentially nothing) to existing chromosomes to prevent loss of genetic info after replication. As the chromosome is further replicated, more and more of the end is not replicated to an extent that the replicated chromosome's sequence at the end, which would have coded for a gene in the chromosome which it was replicated from, codes for a nonfunctional gene. When this happens, chromosomes can't replicate and cells undergoes apoptosis and hence aging. I could be wrong though hopefully others would clarify it more!

 

[bigTOOTHguy]

Still kinda lost...

 

[Illfavor]

Hopefully this clears things up; it worked for me!

 

[LazyP]

Hopefully this clears things up; it worked for me!

Precise and concise! 👍

 

[bigTOOTHguy]

So if im correct, our telomeres eventually shorten and the repeated segments are no longer provided to allow continuation of the DNA replication ?

 

[vash429]

I think they get degraded over time and that is one of the reasons we age. ( double check me on that that's right out of the top of my head)

 

[Dotoday]

Telomeres shorten without telomerase. Our cells do not have telomerase, that is why telomeres shorten. Stem cells and cancer cells have telomerase and that is why they do not age.

Secondly, lagging strand is the one that overhangs. Therefore, telomeres and the shortening appear on the lagging strand.

Hope this helped. Good luck.

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