The nucleic acids, deoxyribonucleic acid (DNA) and
ribonucleic acid (RNA), are one of the basic classes of macromolecules
studied in biochemistry. Nucleic acid, so called because of its prevalence
in cellular nuclei, is the generic name of a family of biopolymers. The monomers
are called nucleotides, and each consists of three components: a nitrogenous
base (either a purine or a pyrimidine), a pentose sugar, and a phosphate group.
Different nucleic acid types differ in the specific sugar found in their chain.