What is the fundamental, defining chemical distinction differentiating the core pentose sugar found — Biomolecules Chemistry Question

💡 Solution & Explanation

The pentose sugar in RNA is $\beta$ - $D$ -ribose. In DNA, the sugar is $\beta$ - $D$ -2-deoxyribose, which structurally differs from ribose solely by the absence of an oxygen atom (and thus the absence of a hydroxyl group) specifically at the $C-2'$ carbon position.