Biology 1001A Lecture Notes - Lecture 9: Okazaki Fragments, Dna Clamp, Dna Replication
Document Summary
Pre lecture: purine and pyrimidine base-pairing in dna/rna, nucleotides consist of 5c deoxyribose sugar, a phosphate group, and 1 of. Okazaki fragment one nucleotide at a time using its 5"-3" exonuclease activity and replaces rna nucleotides with dna nucleotides using its 5"- 3" polymerizing activity: dna ligase seals the break between lagging strand fragments, last rna primer on lagging strand can be removed but not replaced, telomerase extends 3" end of template strand with embedded rna template. Dna backbone: 3" has free hydroxyl group (oh, 5" has free phosphate, double stranded helix shaped, components necessary for dna synthesis, replisome. Complex molecular machine that carries out replication of dna. Contains 2 molecules of dna polymerase to replicate both strands (includes all proteins) simultaneously. One replisome for both strands: dna template, rna primers, enzymes (helicase, dna polymerase iii and i, topoisomerase, primase, Chromosomes number does not change during s-phase (two sister chromatids together considered chromosome)