BIOLOGY 1113 Lecture Notes - Lecture 31: Telomerase, Telomere, Somatic Cell

• School: Ohio State University
• Department: Biology
• Course: BIOLOGY 1113
• Professor: Eric Danhart

Document Summary

All credit goes to freeman biology 6th edition 2017. Telomere- end region of eukaryotic chromosome(linear), do not code for protein, containing repeated sequence of dna. Made of short stretches of bases repeated(ttaggg). Telomerase only works in cells producing gametes, which forces somatic. Enzyme adding dna to telomeres preventing shortening, catalyzed dna synthesis guided from rna template, part of enzyme. cells to get shorter/smaller as individuals age. Number of cell divisions possible for somatic cell limited by initial length of. Overactive telomerase= cancer, however, telomerase would be most active telomeres. in embryos. Ability of dna polymerases to select correct nucleotide to add to growing strand is a result that correct base pairs are most energy efficient, and have distinct shapes. Dna polymerase error rate is about 1/100,000, however actual replication error rate is 1/1 billion. Exonuclease- enzyme removing nucleotides from ends of dna strands.