RULE ONE:Observe carefully the double stranded DNA given piece. Specify the transcribed strand ( template) and the non-transcribed strand. Write them on your copybook specifying the name of each. Try to separate every 3 letters by a dash ( because every 3 nucleotides represent one codon and will code for ONE amino acid only).
Transcribed/template DNA strand:
TAC – TGC- CTA- GTC- GGC- GTT- CGC- CTT- AAC – CGC TGT-ATT.
The Non- transcribed DNA Strand:
RULE TWO: Write the m-RNA in a complementary way to the transcribed DNA strand. (A of the m-RNA binding with T of the DNA ; U of m-RNA binding with A of DNA).
the m-RNA :
Note: to verify your m-RNA correct sequence, just compare it to the DNA non-transcribed strand, it should have the same sequence but instead of T & m-RNA will have a U.
The non-transcribed DNA strand:
ATG-ACG- GAT– CAG- CCG- CAA- GCG–GAA–TTG–GCG–ACA- TAA.
RULE THREE: Use the genetic code to determine the correct amino-acid sequence in the chain coded by the m-RNA .
This genetic code is like a dictionary translating two languages : that of m-RNA to that of amino-acids. So what you see on your left is the code of the m-RNA ( three letters) and on your right is the symbolic name of the amino-acid. All you have to do is to follow the positions of the letters ( codons of RNA) on the table and find its match of the amino-acid.
Met – Thr – Asp- Gln – Pro- Gln – Ala – Glu – Leu – Ala – Thr – .
Note: Usually the synthesized amino-acid chain starts with Methionine (Met) and the last codon in the m-RNA is a stop codon that does not code to any amino-acids. (The number of amino acids is usually less than the number of the codons of the m-RNA by one )
And here you are, the amino-acid sequence completed!!