How would I write the amino acid sequence of the polypeptide?

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reading mRNA codons from left to right: CUGUUCAGGUGUUAG
How would I write the amino acid sequence of the polypeptide?
 
You need to look at a genetic code chart for this one, unless you have it memorized. Here is one: http://www.mun.ca/biology/scarr/MGA2-03-28.jpg

Here is an example of how to write them. Take the first three letters, CUG. Look at the 'first letter' C on the chart. The next letter is U. While still on the row the C is on, go over to the U on the second letter. The last letter is G. In the same box, go down to G. This specific chart is very handy and provides all the letter combinations, but most don't have it. You now know what animo acid corresponds with CUG: Leucine or abbreviated Leu.

Have fun!
 
Assuming that this sequence is from 5' to 3' (this is the direction mRNA is translated), the amino acid sequence from n-terminus to c-terminus would be as follows:

Leucine - Phenylalanine - Arginine - Cysteine

This is because the five codons here correspond to the following. (The last codons signals for peptide synthesis to stop, and does not correspond to an amino acid.)

CUG Leucine
UUC Phenylalanine
AGG Arginine
UGU Cysteine
UAG (stop)

This can be found using an RNA codon table like the one found at http://en.wikipedia.org/wiki/Codon .

One thing you might want to think about is that CUG is not a start codon. That means that in a cell, translation of exactly this piece of mRNA wouldn't occur. If this is for an assignment or something, though, they probably just want to know what amino acids would theoretically match these codons.
 
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