Sunday, December 27, 2009

If a coding strand of DNA is 18-nucleotides...?

If a coding strand of DNA is 18-nucleotides, how many amino acids will be in the polypeptide that is formed? How many nucleotides will be in the mRNA? How many anticodons will be there?If a coding strand of DNA is 18-nucleotides...?
If you think about the answer to your previous question, you should be able to figure this one out. But here are some hints:

nucleotides in mRNA = nucleotides in DNA.

nucleotides in mRNA 梅 3 = number of codons

number of codons 鈥?1 = number of amino acids (because the last codon is a stop codon that doesn't code for an amino acid).

Anticodons are not part of the mRNA, but are part of the tRNA. It doesn't really make sense to ask how many anticodons there will be. I guess the best answer you could give is the same as the number of amino acids. (Why not anticodons = codons? Because the last codon, the stop codon, does not base pair with a tRNA, but with an enzyme called a release factor.)

Please don't thumb me down for not giving you the answer. I am trying to help you LEARN, and if the answers are just given to you with no effort on your part, you'll have no incentive to remember how to get them... which will come back to bite you come exam time!

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