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functional group

(Encyclopedia)CE5 functional group, in organic chemistry, group of atoms within a molecule that is responsible for certain properties of the molecule and reactions in which it takes part. Organic compounds are f...

Furneaux Group

(Encyclopedia)Furneaux Group fûrˈnō [key], about 25 islands, c.900 sq mi (2,330 sq km), Tasmania, SE Australia, in Bass Strait between Tasmania and the Australian mainland. The largest is Flinders Island, and th...

nitro group

(Encyclopedia)nitro group, in chemistry, functional group that consists of a nitrogen atom joined to two oxygen atoms. Compounds that contain a nitro group, e.g., picric acid and trinitrotoluene (TNT), are called n...

aryl group

(Encyclopedia)aryl group ârˈĭl [key], in chemistry, group of atoms derived from benzene or from a benzene derivative by removing one hydrogen that is bonded to the benzene ring (see radical). The simplest aryl g...

Local Group

(Encyclopedia)Local Group, in astronomy, loose cluster of at least 40 nearby galaxies, including our own Milky Way galaxy, the Andromeda Galaxy, and the Magellanic Clouds. The Local Group is spread over an ellipsoi...

therapy group

(Encyclopedia)therapy group: see group psychotherapy. ...

pressure group

(Encyclopedia)pressure group, body, organized or unorganized, that actively seeks to promote its particular interests within a society by exerting pressure on public officials and agencies. Pressure groups direct t...

carbonyl group

(Encyclopedia)carbonyl group kärˈbənĭl [key], in chemistry, functional group that consists of an oxygen atom joined by a double bond to a carbon atom. The carbon atom is joined to the remainder of the molecule ...

carboxyl group

(Encyclopedia)carboxyl group kärbŏkˈsĭl [key], in chemistry, functional group that consists of a carbon atom joined to an oxygen atom by a double bond and to a hydroxyl group, OH, by a single bond. Carboxylic a...

prosthetic group

(Encyclopedia)prosthetic group, non-amino acid portions of certain protein molecules. The key part of the prosthetic group may be either organic (such as a vitamin) or inorganic (such as a metal) and is usually req...