Choose the right answer It is possible to convert the cysteine that is a part of
ID: 69683 • Letter: C
Question
Choose the right answer
It is possible to convert the cysteine that is a part of Cys-tRNACys (the tRNA that would incorporate Cys into a growing peptide) to Ala by a catalytic reduction. If the resulting Ala-tRNACys were added to a mixture of ribosomes, all the other tRNAs and amino acids, all of the cofactors and enzymes needed to make protein in vitro, and mRNA for hemoglobin, where in the newly synthesized hemoglobin would the Ala from Ala-tRNACys be incorporated?
A) Nowhere; this is the equivalent of a nonsense mutation
B) Wherever Ala normally occurs
C) Wherever Cys normally occurs
D) Wherever either Ala or Cys normally occurs
E) Wherever the dipeptide Ala-Cys normally occurs
Explanation / Answer
When Cys-tRNACys is added to Ala and the resultant Ala-tRNACys were added to a mixture of ribosomes, other tRNAs, amino acids, cofactors and enzymes to make mRNA of hemoglobin then the Ala-tRNACys incorporated wherever Cys normally occurs. Thus, option C is correct.