Question

What is the importance of the 2′ hydroxyl group in the ribose sugar of an RNA molecule?

Check all that apply.

View Available Hint(s)

Hint 1. Properties of an hydroxyl groupopened hint

A hydroxyl group has the formula OH. Water, alcohols, carboxylic acids, and other hydroxy-containing compounds can be deprotonated owing to the high electronegativity of oxygen, resulting in a stable conjugate base. Hydroxy-containing compounds are also able to form hydrogen bonds, which lead to higher boiling and melting points than found for the similar compounds that lack this functional group. Organic compounds, which are often hydrocarbons and thus poorly soluble in water, become water soluble when they contain two or more hydroxyl groups, as illustrated by sugars and amino acids. Finally, hydroxyl groups make a compound more reactive by readily participating in dehydration and hydrolysis reactions.

The 2′ hydroxyl groups

Check all that apply.

make RNA molecules more stable than DNA.

allow RNA to form oligomers.

are critically involved in catalytic mechanisms.

give RNA a functionality that is lacking in DNA.

do not play any important roles in RNA molecules.

Answer 1

The 2' hydroxyl group in RNA helps to form A- helix and it can attack on adjacent phosphatediester to cleave the backbone. Thus it makes RNA more susceptible than DNA and so first option is ruled out.

The phosphate group allows RNA to form oligomers not hydroxyl.

Hydroxyl group may not be necessarily involved in catalytic activity.

However, the hydroxyl group gives functionality that is lacking in DNA. These functionality makes RNA different from RNA. Hence answer is option 4) give RNA a functionality that is lacking in DNA.

Of course last option is not correct.