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Telomeres shorten because we have linear chromosomes and it is physically impossible to replicate them without losing a bit off the ends (because in order to ex
by astazangasta 11y ago
Telomeres shorten because we have linear chromosomes and it is physically impossible to replicate them without losing a bit off the ends (because in order to extend strand 1, you need to template off strand 2, so the end of strand 2 can't be copied).
The telomere is a solution to this problem; you just pad the ends of your chromosomes with useless repetitive sequence so if you do lose a bit while replicating it doesn't matter. Any anti tumor properties of this system are an ancillary benefit.
- seanwilson 11y ago> Telomeres shorten because we have linear chromosomes and it is physically impossible to replicate them without losing a bit off the ends If that were true though wouldn't successive newborns have shorter and shorter telomeres?
- astazangasta 11y agoNo, there is a specialized enzyme called telomerase which is responsible for lengthening telomeres. It is active in germline cells and most stem cells, allowing those cells to safely and indefinitely replicate. The enzyme is basically a piece of RNA template that you can slap onto the ragged end of the chromosome and hold in place to allow extension.