Nucleic Acid

Nucleic acids are a family of biopolymers made up of monomeric constituents called nucleotides. Nucleic acids are so-called for their roles in the nucleus of a cell. The most common nucleic acids are DNA and RNA .


A generalized nucleotide contains three structures: a nitrogenous, heterocylic nucleobase; a pentose sugar; and one or more phosphate group(s). A nucleotide without any phosphate groups attached is called a nucleoside.

As with proteins, nucleic acids can be considered to have multiple levels of organisation: the primary structure, for instance, would be considered the sequence of nucleobases in the nucleotides. RNA has be shown to fold back on itself due to complementary base-pairing to provide a secondary structure. The tertiary structure of some nucleic acids, such as the RNA enzymes (ribozymes) that make up ribosomes, contributes to their specificity of catalytic function.