<biochemistry> Phosphate esters of nucleosides. The metabolic precursors of nucleic acids are monoesters with phosphate on carbon 5 of the pentose (known as 5' to distinguish sugar from base numbering).

However many other structures, such as adenosine 3'5' cyclic monophosphate (cAMP) and molecules with 2 or 3 phosphates are also called nucleotides.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)