Old cells die through apoptosis or necrosis and new cells replace them through cell division and replication. Does this process decrease in frequency over time? Why does that happen?
In: Biology
A lot of factors play a role in aging, but an important one that’s easy to understand is telomere shortening. As you may know, the process of transcription transcribes DNA into mRNA to take to the ribosome to be the blueprint for your proteins. Most of this DNA gets transcribed perfectly; however, your RNA polymerase isn’t that great at reading the ends of DNA strands (called telomeres). So, your body has to use telomerase to artificially lengthen the ends of your DNA strands, so that the RNA polymerase can finish reading them. Over time, our telomerase doesn’t do its job right every now and then, and just that little bit of DNA strand gets lost and doesn’t become proteins. On a long enough timeline, that leads to the body missing a fair amount of proteins that it needs, and this has a noticeable affect on aging, especially in the brain.
Interestingly, studies are now also finding that artificially giving extra telomerase to mice has caused their brains to slow down the aging process, which has huge implications for diseases like Alzheimers.
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