In DNA structure, the sugar attached to each nucleotide’s phosphate group and nitrogenous base is deoxyribose.
Deoxyribose is a five-carbon sugar, or pentose. Its name reflects the fact that it has one less oxygen atom than ribose, the sugar found in RNA. This small chemical difference contributes to DNA’s greater stability, making DNA well suited for long-term storage of genetic information.
A DNA nucleotide contains three parts: deoxyribose, a phosphate group, and one nitrogenous base. The sugar and phosphate groups form the alternating backbone of each DNA strand, while the bases point inward and pair across the double helix.
A common mix-up is calling the sugar simply “ribose.” Ribose belongs to RNA, whereas deoxyribose belongs to DNA. The distinction between the two sugars is central to the chemical differences between these nucleic acids.