Question

The protein P, the oligosaccharide O, and the oligonucleotide N are composed of $100$ amino acid residues, $100$ hexose residues, and $100$ nucleotides, respectively. Which one of the following orders of molecular weights is correct?

• A. P $>$ O $>$ N
• B. P $>$ N $>$ O
• C. N $>$ O $>$ P
• D. O $>$ P $>$ N

Answer 1

The correct option is C N $>$ O $>$ P

The average molecular weight of a nucleotide is 325 Daltons or g/mol. The average molecular weight of an amino acid is 110 daltons or g/mol. The average molecular weight of hexose is 180.156 g/mol. Hence, oligonucleotide (N) composed of 100 nucleotides will have highest molecular weight followed by oligosaccharide (O) composed of 100 hexose residues. The protein composed of 100 amino acids will have the least molecular weight.

Thus, the correct answer is option C.