Questions about DNA Replication: RNA Primer, 3' to 5', TRNA

[Dual Op Amp]

I have a question, I saw many animations of DNA replication. But there's a couple of questions I don't understand.
1. What is the difference between RNA primer and DNA?
2. When it says 3' to 5', what's that?
3. Where is TRNA made?

 

[iansmith]

1. What is the difference between RNA primer and DNA?

The RNA primer is there to allow the polymerase to initiate replication. The primer is a short sequence and it is complementary to the parental strand. The RNA primer is sequenced by RNA primase.

2. When it says 3' to 5', what's that?

It has to do with the DNA molecule. Look at the following picture
http://www.colorado.edu/MCDB/MCDB1150/ohd/dnamolecules.JPG
You see how the each nucleotides are attached. So when the the DNA polymerase is moving along it goes from the 3' end to the 5' site.

3. Where is TRNA made?

tRNA is synthesis by a RNA polymerase in the same fashion than normal gene transcription. The strucuture is a normal feature of RNA and will fold without any help. The acceptor site the added but it not well known were the this is happening.

 

[Drayakir]

1.) RNA primer is the thing that lays down the primers. Primers are a sequence of complementary RNA bases to which the DNA polymerase begins attaching its DNA nucleotides. This is done in both the leading and lagging strand, except the lagging strand has more primers.

2.) During RNA synthesis, the DNA strand is read in a 3' to 5' direction. 3' and 5' are two ends of the DNA strand.

3.) I'm not sure, but I think tRNA is made via RNA replication

A good site for info is www.wikipedia.org ; or you can just google this stuff.

EDIT: Sorry, I see someone has answered this already...

 

[Maritza]

The RNA primer is there to allow the polymerase to initiate replication. The primer is a short sequence and it is complementary to the parental strand. The RNA primer is sequenced by RNA primase.

Why RNA primer instead of DNA? does the OH in RNA molecule have something to do with this? Or what else can be determining?

Edit: maybe 3' OH end supplies the energy for synthesis?

 

[gamze]

DNA polimerases cannot work without a 3' OH end, but RNA polimerase can.