Biochemistry 2280A Lecture Notes - Lecture 7: Dna Replication, Semiconservative Replication, Polynucleotide

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 2280A
• Professor: Derek Mc Lachlin

Document Summary

Complimentary nucleotides attach to the template strand to replicate the original polynucleotide: each replicated chromosome contains 1 old strand (template/parent) and 1 new strand (daughter) 15n and 14n dna can be separated using a density gradient because 15n is heavier, so it will go through the gradient faster: this experiment demonstrated that dna replication is semi-conservative. Replication initiation: replication begins at dna sequences called replication origins, eukaryotes have multiple replication origins. Priming: dna primase enzyme synthesizes a short (approx. 10 nucleotides long) rna primer 5" to 3" on each of the dna strands by complimentary base pairing: this is needed because dna polymerase can only attach new dna nucleotides to an existing strand of nucleotides. Dna synthesis: dna polymerase iii synthesizes dna in the 5" 3" direction by adding nucleotides onto the. In humans, expression of the telomerase enzyme stops in somatic (bodily) cells shortly after birth.