Science glossary film: Functional group

An atom or group of atoms within a compound that reacts in a characteristic way, giving molecules particular chemical properties. Organic compounds are usually classified according to which functional groups they contain. Alcohols, like those found in antifreeze and hand sanitisers, always contain the hydroxyl group, which has the formula OH. And the strong-smelling aldehydes, which include the chemicals that give cinnamon and vanilla their distinctive scents, always contain the formyl group, which has the formula CHO.

Organic compounds are usually classified according to which functional groups they contain. Alcohols, like those found in antifreeze and hand sanitisers, always contain the hydroxyl group, which has the formula OH. And the strong-smelling aldehydes, which include the chemicals that give cinnamon and vanilla their distinctive scents, always contain the formyl group, which has the formula CHO.