A messenger RNA is 5′-AUGGCUUGGAAAUAG-3′…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A messenger RNA is 5′-AUGGCUUGGAAAUAG-3′. It is read from the first base in groups of three. The last codon that is read is a stop codon. Find the number of codons, the number of amino acids in the peptide that is made, and the number of peptide bonds in it.
Need a reminder? The key ideaShow
In B-DNA the base pairs are apart and there are about base pairs in a turn. A codon is three bases, and a stop codon does not code for an amino acid. The mass fraction of an element in a molecule is .
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Codons. There are 15 bases, so codons: AUG, GCU, UGG, AAA and UAG.
Step 2. Stop codon. UAG is a stop codon, so it adds no amino acid.
Step 3. Amino acids. The other four codons give 4 amino acids: Met, Ala, Trp and Lys.
Step 4. Peptide bonds. .
Answer: 5 codons, 4 amino acids and 3 peptide bonds.
Check. The number of bases that code for amino acids is , and the stop codon makes the total 15.
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