Lecture 2-4
Lecture 2-4 DNA replication Meselson and Stahl model- Conservative, semiconservative and dispersive.
Prokaryotic DNA Replication Prokaryotic chromosomes are circular molecules of DNA. Replication begins at OriC and proceeds in both directions around the chromosomes.
Enzymes and proteins relevant to replication Helicase-unwinds double helix. Primase- Synthesizes RNA primers. Single-stranded binding protein-protein that binds to single stranded DNA, fills gaps and stabilizes. DNA gyrase-Relieves torque. DNA polymerase III-synthesizes DNA. DNA polymerase I- erases primers and fills gaps. DNA ligase-Joins ends of DNA segments and DNA repair. Replication fork-structure that forms during replication. DNA Replication in prokaryotes
Semi discontinuous DNA replication DNA polymerase III adds nucelotides to the 3’ end of th daughter strand of DNA which means DNA synthesis will only ever occur in the 5’ to 3’ direction. DNA strands are antiparallel. The Leading Strand synthesizes DNA continuously as in the same direction as the replication fork.
Prokaryotic DNA Replication Prokaryotic chromosomes are circular molecules of DNA. Replication begins at OriC and proceeds in both directions around the chromosomes.
Enzymes and proteins relevant to replication Helicase-unwinds double helix. Primase- Synthesizes RNA primers. Single-stranded binding protein-protein that binds to single stranded DNA, fills gaps and stabilizes. DNA gyrase-Relieves torque. DNA polymerase III-synthesizes DNA. DNA polymerase I- erases primers and fills gaps. DNA ligase-Joins ends of DNA segments and DNA repair. Replication fork-structure that forms during replication. DNA Replication in prokaryotes
Semi discontinuous DNA replication DNA polymerase III adds nucelotides to the 3’ end of th daughter strand of DNA which means DNA synthesis will only ever occur in the 5’ to 3’ direction. DNA strands are antiparallel. The Leading Strand synthesizes DNA continuously as in the same direction as the replication fork.
