Is DNA dispersive, semi conservative or conservative ?
DNA is semiconservative and bidirectional (both strands are copied at the same time
what are the 2 minimum requirements for replication of DNA?
- template strand-orginal DNA
- DNA poly- enzymes that polymerizes nucleotide into strand of dna
which direction are both strands synthesized from ?
they are synthesized from the 5’-3’ end
what is the leading and lagging strand
the 3-5 template strand is the leading stand
the 5-3 strand is the lagging strand copied. short segments called okazaki strands
how many DNA pol and termination sites does bacterial DNA replication have ?
5 DNA pol and 10 termination sites (Ter)
what is the OriC in bacteria ?
it is define as the single orgin of replication and it A-T rich due to easier to break bonds
what is the make up of the termination site (Ter) in bacteria?
it is comprised of 10 copies of 23 bp and is bound by the Tus
in order what is the function of each thing in bacterial replication
- DNaA (the initiator) binds to OriC and melts the DNA
- DnaB(helicase) circles the lagging strand and use atp hydrolysis to unwind DNA
- single stranded dna is bound to SSBs proteins to prevent nucleases
4.DnaG (primase) make an RNA primer at replication fork - Sliding clamp beta loads on dna
- 3 DNA pol III attached to slide clamp beta and 2 DNA pol III are on the lagging strand making rna primers to okazaki frags
7.DNA POL II is relased - new sliding clamp make another rns primer to make the next ozazaki frag
- synthesis goes on until replication forks meet the Ter sites
what removes the RNA Primer?
DNA Pol I
What does DNA Ligase do ?
it catalyzes the formation of phosphodiester linkage between okizai fragments
how is the bacterial DNA supercoiled again?
while the replication fork is moving along DNA positive supercoiling is generated ahead and the replication strands are being negatively supercoiled
