00:03
You're trying to replicate a dna replication process in your lab to control it at a molecular level.
00:11
What order of event would you need to occur with the ligand strand as you design the experiment? so the natural order of the dna replication start out with first step, the helicase unwind the dna double helix.
00:31
I'm going to write down all the steps.
00:54
The next step, you will need primase.
01:02
The primase will synthesize short rna primer that is complementary to the dna template.
01:09
So the second step, primase make rna primers.
01:21
Again, the rna primers will be complementary to dna strand.
01:30
The third step, you will have dna polymerase to add nucleotides to the three prime end of the rna primer.
01:41
And it will actually work in the opposite direction of the replication fork.
01:48
So you'll have dna polymerase, typically number three, add nucleotides to the three prime end of the primer.
02:23
The rna primer is needed because dna polymerase three is not able to initiate the new dna strand.
02:30
So it must need a primer to begin a sequence and then it will add nucleotides to the three prime end of the primer.
02:38
And it only works in a five to three direction.
02:50
And so this is why the primers are needed.
02:55
So the next step, once the new strand is being done and the polymerase three will reach the previous rna primer and of course it stops.
03:08
And then once the okazaki fragment is done, the dna polymerase one is going to remove the rna primer.
03:22
As i just mentioned, this small piece that is synthesized by dna polymerase three, we call it okazaki fragment.
03:31
And again, it will stop at the previous okazaki fragment.
03:37
So the next step, once this okazaki fragment is done, you need dna polymerase one to remove the primer.
04:04
Because it's a dna strand, you do not want to have rna in there.
04:08
So the rna primer is just used to start the new sequence.
04:12
Once the new okazaki fragment is being done, the rna primer must be removed...