Chapter 3: DNA Replication Flashcards
Semi-conservative??
- one DNA strand from parental helix acts as the template
- one newly synthesized strand
dNTPs are added to the _’ end of the chain
3’ OH
DNA is synthesized _’ to _’
5’ to 3’
The template for DNA synthesis must be single or double stranded?
- single!
- there must be a strand that extends on past the template
What are the primary replication enzymes?
Poly I and Poly III
there are __ nt/s in bacteria and - nt/s in humans?
- 850
- 60-90
Initiation of Replication:
- Replicator ( OriC in E.coli)
L> DnaA?
- initiator proteins bind.
L> leads to the denaturation of DNA
L> binds at 9-bp
Initiation of Replication:
- Replicator ( OriC in E.coli)
L> DnaB ?
- helicase….binds to DNA with the help of DnaC
L> break H-bonds btwn bases
L>r 13-bp since its rich in A and T
Initiation of Replication:
- Replicator ( OriC in E.coli)
L> DnaG???
primase binds….its a DnaG gene product…. DNA polymerase binds
What are the three core enzymes of DNA Poly III?
- DNA E
DNA Q
HOLE
What are the three enzymes of DNA poly I?
- DNA E , DNA Q , DA e
Replication fork:
- The double stranded DNA section __ to reveal __ template strands
- opens
ssDNA
Replication fork
- Leading strand?
- 5-3 strand synthesized continuously
Replication fork
lagging strand?
- 3-5’ strand synthesized discontinuously
Eukaryotic Polymerases?
- Pol aplha/primase?
- initiates new strands in replication via primase
L> Poly a adds 10-20 nt of DNA
