Biology 2581B Quiz: Primers
Document Summary
Dna primase (an rna polymerase) doesn"t need base paired ends. Uses ribonucleoside triphosphate to synthesise short rna primers. 10 nucleotides long, at intervals of 100-200 nucleotides in eukaryotes. Only added to leading strand at beginning, but continuously added to lagging. Primers less accurate 1 in 105 mistakes. Seen as suspect and removed by dna because they have ribose. When dna is opened up at origin, single strand dna acts as a template. Dna p needs a 3" end to start replication. Dna strands open up, helicase enters to push parental strands open, then dna primase (an rna polymerase doesn"t proofread/self-correct) enters. Replication started by an rna primer formed by an rna polymerase called dna primase. Every okazaki fragment needs a new primer. Rna primers remove due to high error rate. Lagging strand 3 additional enzymes needed for lagging strand synthesis- Nuclease recognises rna primer, chews away rna part, degrades rna primer. Repair dna polymerase replaces rna with dna.