What structural feature distinguishes RNA from DNA?

The distinguishing structural feature that sets RNA apart from DNA is that RNA contains ribose sugar, while DNA contains deoxyribose sugar. The presence of ribose in RNA means that it has a hydroxyl (-OH) group attached to the 2' carbon of the sugar, which contributes to its chemical reactivity and stability in different biological processes. In contrast, deoxyribose in DNA lacks that hydroxyl group and instead has a hydrogen atom, making the molecule more stable and less reactive, which is ideal for its role in storing genetic information.

The difference in sugar type also plays a significant role in how these nucleic acids function. RNA's ribose can participate in various biochemical reactions and is more suited for its diverse roles in protein synthesis and regulation of gene expression.