Illustrated Glossary of Organic Chemistry

Phosphate ester: An ester derived from an alcohol and phosphoric acid. Also called organophosphate compounds because these molecules have a phosphate group bonded to carbon.

	+		- H2O		or
Generic alcohol		Phosphoric acid		Generic phosphate ester		Phosphate ester conjugate base

In DNA and RNA, a phosphodiester group (in the black circle) joins the 3'-carbon on the ribofuranose of one nucleobase to the 5'-carbon on the next nucleobase.