Question

If the DNA sequence in the question above is at the BEGINNING of a gene, what are the first 2 amino acids that will be joined at the ribosome? Remember there is a START codon. Use the information on this chart to answer the question.

asparagine, alanine

methionine, glutamine

leucine, alanine

alanine, lysine

methionine, asparagine

Answer 1

Ans: The sequence is not given in the question, so i'm considering a sequence just to explain the question.

So as we all know that DNA is double stranded and during transcription one of its strand is used as template and the other one is used as coding strand. Template strand  serves as a template for synthesis of a complementary RNA transcript and Coding strand is identical to the RNA transcript in sequence, except that it has uracil (U) bases in place of thymine (T) bases.

Now lets take the sequence and consider that it is the template strand:

CCC GGA TAC GTT ACA TGG TAT GGC TTC GTC; So the coding strand is GGG CCT ATG CAA TGT ACC ATA CCG AAG CAG. Now the RNA transcript is identical to this coding strand except in the place of Thymine(T) RNA trasncript has Uracil(U). So RNA transcript is GGG CCU AUG CAA UGU ACC AUA CCG AAG CAG and as we all know that translation starts from the initiation codon AUG and AUG codon codes for Methionine. Now the second codon after initiation codon is CAA which encode Glutamine amino acid.

So, the first 2 amino acids joined at the ribosome is Methionine and Glutamine.