A lone pair on a nitrogen atom also makes bases of many organic compounds such as pyridine, drawn below. Nitrogen-containing organic bases are the central stairsteps in the double-stranded DNA of the genes, where the bases provide the means of encoding genetic information. In the porphyrin ring, seen opposite, nitrogen atoms with their lone pairs are the ligands to the central iron atom. Many other nitrogen-containing ring compounds are bound to enzymes or are used as carriers of chemical energy.

A lone electron pair on a nitrogen atom in an organic ring can bond to a proton, just as in the conversion of to . Like ammonia, pyridine and other such organic nitrogen compounds are bases.