What distinguishes ribose from deoxyribose?

Ribose is characterized by the presence of a hydroxyl group (-OH) at the 2nd carbon in its structure. This hydroxyl group plays a crucial role in differentiating ribose from deoxyribose, which instead has a hydrogen atom at this position, making it "deoxy" or lacking an oxygen atom at the second carbon. This structural difference is foundational, as it affects the stability and functionality of RNA (which contains ribose) compared to DNA (which contains deoxyribose).

Understanding this distinction is essential because it influences the structural properties of nucleic acids. RNA is typically more reactive and less stable than DNA partly due to this hydroxyl group. Additionally, ribose is a five-carbon sugar (pentose), not a six-carbon sugar, and it is not exclusive to DNA, as it is found in RNA where it is vital for the synthesis of RNA molecules.