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Old 12-14-2015
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Angry Biochemistry helppp !!

hi all
i need help in answering this question and plz plz explain how you answer it ?

A DNA strand with the sequence AACGTAACG is transcribed. What is the sequence of the mRNA molecule synthesized?
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Old 12-15-2015
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Quote:
Originally Posted by Fight4You View Post
hi all
i need help in answering this question and plz plz explain how you answer it ?

A DNA strand with the sequence AACGTAACG is transcribed. What is the sequence of the mRNA molecule synthesized?
This is probably the coding strand (5'-3') of the dsDNA segment.
5'-AACGTAACG-3'
3'-TTGCATTGC-5'


The 3'-5' strand (template strand) is read in the 3-5 direction, and the product is synthesized in the 5'-3' direction, as the RNA polymerase moves forward along the 3-5 strand. Now since mRNA synthesis is both complimentary and antiparallel, you'll end up with a mRNA strand that base-pairs with the 3'-5' DNA strand, and antiparallel to it, thus making it in the 5'-3' direction.

So, the mRNA transcript will be identical to the 5'-3' strand, with the (T's as U's, since RNA doesn't have T's)

The mRNA sequence should be
AACGUAACG
The rule is, always assume polarity is in the 5'-3', unless mentioned otherwise!
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The above post was thanked by:
CleverFOX (12-22-2015), Fight4You (12-22-2015)
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Old 12-22-2015
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Quote:
Originally Posted by gokulramani View Post
This is probably the coding strand (5'-3') of the dsDNA segment.
5'-AACGTAACG-3'
3'-TTGCATTGC-5'


The 3'-5' strand (template strand) is read in the 3-5 direction, and the product is synthesized in the 5'-3' direction, as the RNA polymerase moves forward along the 3-5 strand. Now since mRNA synthesis is both complimentary and antiparallel, you'll end up with a mRNA strand that base-pairs with the 3'-5' DNA strand, and antiparallel to it, thus making it in the 5'-3' direction.

So, the mRNA transcript will be identical to the 5'-3' strand, with the (T's as U's, since RNA doesn't have T's)

The mRNA sequence should be
AACGUAACG
The rule is, always assume polarity is in the 5'-3', unless mentioned otherwise!

Thankkkkkkkkk you so much
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