The structure of ribose and deoxyribose are nearly identical, with one key difference. Ribose consists of a hydroxyl group at carbon 2. In contrast, deoxyribose has a hydrogen atom at the same carbon; it lacks an oxygen atom. Because of this, the deoxyribose molecule is more stable than the ribose molecule. The molar mass of ribose is 150.13 g/mol while deoxyribose has a molar mass of 134.14 g/mol. The difference in molar mass is because of the lack of one oxygen atom in the deoxyribose molecule.