A.Transcribe the following nucleotide sequence into its complementary strand of mRNA: TAC TTA CGC TAA ATC

Translate your sequence of mRNA from part a into the appropriate sequence of amino acids

To do this correctly, you need to know whether this is the sense or antisense strand. The sequence should have either been labelled 5' TAC...3' for the sense strand or 3' TAC....5' for the antisense strand.

It makes a big difference. The sense strand carries the code, the antisense strand carries the sequence complementary to the code and acts as the template for mRNA synthesis.

If you have the sense strand here, then the mRNA sequence would be the same, apart from U replacing T,

so UAC UUA CGC UAA AUC then your amino acid sequence would be

Tyr-Leu-Arg- STOP- (Ile)

If you are given the antisense strand, then the mRNA is complementary so

AUG AAU GCG AUU UAG

Met (start) - Asn-Arg-Ile-STOP.

So the second outcome seems more likely, but unless you know which DNA strand you are dealing with, you cannot automatically get it right.

If you weren't given the strand, it would be good if you put in both answers, so teachers are encouraged to set their questions correctly!

Ok, so we know that RNA replaces thymine with uracil and that G bonds with C, while A binds with U/T.
So:

AUG AAU GCG AUU UAG

AUG AAU GCG UTT UAG