Question

If molecular weight of a polypeptide is $15.3$ kDa, what would be the minimum number of nucleotides in the mRNA that codes for this polypeptide? Assume that molecule weight of each amino acid is $90$ Da.

• A. $510$
• B. $663$
• C. $123$
• D. $170$

Answer 1

The correct option is A $510$

As this polypeptide is 15.3kDa in weight, by dividing it with the molecular weight of each amino acid ( 90 Da ) we get 170. It means we have 170 amino acids present in this polypeptide.

Each amino acid is coded by a triplet of codon ( 3 nucleotide sequence ), so 3*170 = 510.

So, the correct option is '510'.