Biology Forums - Study Force

Use the following fragment of a polypeptide sequence to perform "reverse translation" to determine the mRNA sequence.
V Asp Trp Leu Lys Gly Asn Thr

 a. Compare your mRNA sequence to the sequence of at least two of your lab mates. Are they the same? Can you use more than one codon for each amino acid?
b. Perform reverse transcription using your mRNA sequence to determine the DNA from which it was transcribed?
c. Explain why the flow of genetic information could not be polypeptide RNA->DNA?

What's with the "V" at the beginning. Is that short for valine?

I'm going to assume it's a typo and only focus on Asp Trp Leu Lys Gly Asn Thr

What's interesting is that due to the wobble hypothesis, each amino acid can have multiple codons.

(a) That said, your code and your classmates may have different sequences of nucleotides that depict the mRNA. That doesn't mean you are wrong, or they are wrong, as multiple codes do translate to the same amino acid.

Asp	Trp	Leu	Lys	Gly	Asn	Thr
GAU, GAC	UGG	UUA, UUG, CUU, CUC CUA, CUG	AAA, AAG	GGU, GGC, GGA, GGG	AAU, AAC	ACU, ACC, ACA, ACG

Here are all the possible codons to generate, so select one from each column. I've randomly selected those underlined.

GAC-UUG-AAG-GGU-AAU-ACG

(b) Lets convert this back to DNA:

GAC-UUG-AAG-GGU-AAU-ACG
CTG-AAC-TTC-CCA-TTA-TGC


Because DNA contains the nucleotide thymine, in mRNA that's replaced with Uracil, among many other reasons.