Biology: DNA (not homework so take your time)

[AFB]

What decides what side of DNA is used for synthesis or are both used. Yes, I know that you can get one from the other, but during sythesis, it matters what side is used. The reason is that it forms different amino acids and it produces a different protien. So, which one is used.

 

[gsellis]

Huh? It you take a pair apart, A goes with T, G goes with C. You split one and you get two of the same DNAs unless something messes it up. Not sure what you mean.

 

[LadyJessica]

You mean for making mRNA? There are initiator sequences that enzymes specifically bind to and start transcribing from there. It should be in your biology text book.

 

[AFB]

Let me make a picture.(I'll edit later) ::



(tRNA)=(mRNA)=(DNA)=(mRNA)=(tRNA)
==A===== U====-AT-==-A-======U
==G=====C====-GC-==-G-======C
==U===== A====-TA-==-U-======A
==A===== U====-AT-==-A-======U
==C=====G====-CG-==C-======G
==A===== T====-AT-==-A-======U
==G=====C====-GC-==G-======C

See, depending on which side you use to make tRNA matters. They become the opposite and make differnet amino acids.

 

[sxr7171]

Originally posted by: LadyJessica
You mean for making mRNA? There are initiator sequences that enzymes specifically bind to and start transcribing from there. It should be in your biology text book.

Your answer is here. mRNA only gets made from the side that has an initiator sequence. mRNA is not made from both strands.

 

[AFB]

Can we get a confirmation ?

 

[sxr7171]

Any basic biology book will state the fact the only one strand is transcribed. A decent google search will confirm that also. Or you could sit here and wait for a third person to basically state the same thing.

 

[AFB]

Originally posted by: sxr7171
Any basic biology book will state the fact the only one strand is transcribed. A decent google search will confirm that also. Or you could sit here and wait for a third person to basically state the same thing.

I will except a link as proof if it is from a some what reliable site. I think your right, I just want a second opinion. Thank you for answering my question.

 

[sxr7171]

Originally posted by: amdfanboy

Originally posted by: sxr7171
Any basic biology book will state the fact the only one strand is transcribed. A decent google search will confirm that also. Or you could sit here and wait for a third person to basically state the same thing.

I will except a link as proof if it is from a some what reliable site. I think your right, I just want a second opinion. Thank you for answering my question.

Here you go (all sites were gotten by typing "DNA transcription" in google):

http://www.ncc.gmu.edu/dna/transcri.htm

http://www.mun.ca/biology/scarr/3250_DNA_transcription.htm

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/Transcription.html

It is the anti-sense strand that is used for transcription and this effectively copies the original sense strand.

 

[AFB]

Thank you so much. I could not find this in my book. Maybe I'm just blind.

 

[sao123]

The strand of DNA used is determined by what side the promoter (the region
of DNA that controls the transcription of the gene) is on. Genes can be on
both strands of DNA, however a gene is only on one strand of DNA(it can't
be on both at the same time), hence why one strand is referred to as the
sense and one is the antisense. Genes are always transcribed running 5' to
3' on the DNA strand.

Hope that helps...