Nucleotides constitute the fundamental monomeric units of nucleic acids (DNA and RNA), defined by a nitrogenous base linked to a pentose sugar via a glycosidic bond, with optional phosphate group attachments distinguishing them as nucleosides or nucleotides. The structural differentiation between deoxyribonucleic acid and ribonucleic acid is determined strictly by the absence of an oxygen atom at the 2' carbon position of the pentose ring in DNA versus its presence in RNA. Within this domain, nitrogenous bases are categorized into purines (adenine, guanine) present universally across both polymers and pyrimidines where thymine is exclusive to DNA while uracil is exclusive to RNA; nucleotide composition dictates polymer stability through hydrogen bonding between complementary base pairs which maintains the double-helical structure.
DNA is a polymer of nucleotides, each composed of three covalently linked parts: a phosphate group, a five-carbon deoxyribose sugar, and a nitrogenous base — a decomposition from which the name deoxy…