Nucleotides Nucleotides are the monomers, building blocks, of nucleic acids (DNA and RNA). Each nucleotide includes three components: a phosphate, a sugar, and a nitrogenous base.The phosphate is bonded to the sugar through phosphodiester bonds and makes up the backbone of the molecule.he nitrogenous bases form the rungs of the ladder and are connected through hydrogen bonds. The phosphate is the same in DNA and RNA, but the sugar can be a ribose (for RNA) or a deoxyribose (for DNA). The latter is a ribose without  de-  one oxygen  -oxy- .