Deoxyribose is the five-carbon sugar that forms the structural backbone of DNA. Its name describes its chemistry: it is ribose missing one oxygen atom — “deoxy” — at the 2′ position, and that small absence makes a large difference, giving DNA the chemical stability it needs to store genetic information for a lifetime. In the double helix, deoxyribose molecules alternate with phosphate groups to form the two rails of the ladder, with the nitrogenous bases — adenine, thymine, cytosine, guanine — attached to each sugar and pairing across the middle. Every cell in every food we eat carries its DNA built on deoxyribose, from the wheat in bread to the bacteria in yoghurt. For nutrition the sugar itself is a curiosity rather than a nutrient; its importance is architectural — the molecular scaffold of heredity.