Question

RNA is a labile molecule due to the presence of:

• A. 3’-OH group
• B. 5’-OH group
• C. 4’-OH group
• D. 2’-OH group

Answer 1

The Correct Option is D

RNA is a labile molecule due to the presence of the 2’-OH group. The 2'-OH group on the ribose sugar in RNA makes the molecule more susceptible to hydrolysis, especially under alkaline conditions. This makes RNA more unstable compared to DNA, which lacks the 2’-OH group (replaced by a 2’-H in deoxyribose).

(1) 3’-OH group: The 3’-OH group is necessary for RNA strand elongation during transcription but does not contribute to its instability.

(2) 5’-OH group: The 5’-OH group is involved in the attachment of nucleotides during transcription but does not significantly contribute to the instability of RNA.

(3) 4’-OH group: This does not exist in the context of the ribose sugar structure of RNA or DNA.

(4) 2’-OH group: The 2’-OH group makes RNA highly reactive and more prone to degradation, especially under alkaline conditions.

Thus, the correct answer is (4) 2’-OH group.

Answer 2

RNA is unstable due to the 2’-OH group, which makes it more prone to hydrolysis in cellular environments. The 2’-OH in RNA, compared to DNA’s absence of this hydroxyl group, contributes to its higher reactivity and lability, leading to faster degradation.