A
deoxyribonucleotide is the
monomer, or single unit, of
DNA, or deoxyribonucleic acid. Each deoxyribonucleotide comprises three parts: a
nitrogenous base, a
deoxyribose sugar, and one
phosphate group. The nitrogenous base is always bonded to the 1' carbon of the deoxyribose, which is distinguished from ribose by the presence of a proton on the 2' carbon rather than an -OH group. The phosphate groups bind to the 5' carbon of the sugar.