00:01
This question asks us to put the enzymes involved in lagging strand synthesis of dna in the correct order.
00:08
So what comes first? well, the first thing that happens is that the dna must be unwound.
00:15
And that's going to be the action of the helicase.
00:18
Basically, it takes the double -stranded helical dna and it unwinds it and gives us access to the two strands.
00:27
And basically, the helicase will go ahead and separate the strands.
00:30
Out to give us a leading strand and a lagging strand.
00:34
So that's the first step.
00:36
Now the second step, the second enzyme involved is going to be the primase.
00:42
Now what happens is the primase adds an rna -based primer.
00:47
And why is it rna? well, it's because dna needs to be added to something that already is there.
00:54
In other words, you can't just start adding bases for dna.
00:59
With rna, if you use a primer, this is possible...