BIO 1140 Lecture Notes - Lecture 11: Dna Replication, Reverse Transcriptase, Hayflick Limit
Document Summary
With replication, that sequence shortens, but protects the coding regions of our chromosomes: it shortens because it cant have any dna nucleotides added to it because there is no primer. When the telomeres are gone, the cell should stop dividing because the coding region of the dna will start to shorten. Hayflick limit: the number of healthy cell division a cell can accomplish: when you reach the limit, the cell will stop dividing (sometimes it dies) and sometimes it stays. Telomerase: add telomeres (increases the length the telomere: it adds the nucleotides by using reverse transcriptase. Some cells divide very often (roots (plants), epithelium (skin, intestines), etc) Some do not divide in adults (rbcs, muscles, most neurons) During the 70s, the big question was how does the cell know what to do and when to do it?". What if something goes wrong: caner, apoptosis, mutations, many consequences and failsafe mechanisms.