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Old 07-12-2011
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DNA DNA replication; Do we need a primer for the leading strand?

is there a primer in the leading strand?
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No the RNA primer is added in short segments to the Lagging strand (composed of short segmented okazaki fragments) by DNA Primase.

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Old 07-12-2011
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Yes I agree with you, but I just read in UW biochem that they have primer in leading strand!!!
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Quote:
Originally Posted by laurier View Post
Yes I agree with you, but I just read in UW biochem that they have primer in leading strand!!!
RNA polymerase does not need a primer...DNA polymerase does...that's the rule

Reference: Kaplan Lecture Notes
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Can you give me the Q # ?
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Quote:
Originally Posted by laurier View Post
is there a primer in the leading strand?
DNA pol does => RNA primase

this is the table for kaplan...

primer.bmp
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Old 07-12-2011
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how to insert image here?
I want to share the diagram
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Old 07-12-2011
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Quote:
Originally Posted by bebix View Post
DNA pol does => RNA primase

this is the table for kaplan...

Attachment 1766
wt i ve seen in kaplan primer is formed in both leading n lagging strand by primase am i rite
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Old 07-12-2011
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here attached the UW diagram,
they said primer in leading strand!!!!

DNA replication; Do we need a primer for the leading strand?-dna-replication.jpg
click image to enlarge
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Quote:
Originally Posted by laurier View Post
here attached the UW diagram,
they said primer in leading strand!!!!
???...I dont see the problem...of course...DNA polymerase needs a primer...
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Quote:
Originally Posted by prepink View Post
???...I dont see the problem...of course...DNA polymerase needs a primer...
He is asking if the leading strand needs a primer at all. Not if the enzyme needs it

And the answer is yes it does. Primers are portion of RNA the make possible for DNA polymerase to start putting the nucleotids. So both the leading and lagging strand need them. The difference is that the Leading strand only needs 1 due to it's continuous replication and the lagging strand needs on for every okazaki fragment

The need of primers is the reason why telomere get shorter in every replication. So if there where no need for primers in the leading strand then one of the strand will always be longer (that's the logic I used to understand and remember the purpose of primers)

Hope this was helpful
Check some replication animation videos in you tube. They helped me a lot when I was learning this
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Old 07-13-2011
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thank you Meli for clarifying this .
I see things clear now
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