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guanine

(Encyclopedia)guanine gwäˈnēn [key], organic base of the purine family. It was reported (1846) to be in the guano of birds; later (1879–84) it was established as one of the major constituents of nucleic acids....

mineral, dietary

(Encyclopedia)mineral, dietary, any of a group of inorganic elements that are essential to humans and animals for normal body function. In nutrition, minerals are those elements for which the body's requirement is ...

barbiturate

(Encyclopedia)barbiturate bärbĭchˈərātˌ [key], any one of a group of drugs that act as depressants on the central nervous system. High doses depress both nerve and muscle activity and inhibit oxygen consumpti...

gelatin

(Encyclopedia)gelatin or animal jelly, foodstuff obtained from connective tissue (found in hoofs, bones, tendons, ligaments, and cartilage) of vertebrate animals by the action of boiling water or dilute acid. It is...

Great Smoky Mountains

(Encyclopedia)Great Smoky Mountains, part of the Appalachian system, on the N.C.–Tenn. border; highest range E of the Mississippi and one of the oldest uplands on earth. The mountains are named for the smokelike ...

Gram's stain

(Encyclopedia)Gram's stain, laboratory staining technique that distinguishes between two groups of bacteria by the identification of differences in the structure of their cell walls. The Gram stain, named after its...

Turner, Tina

(Encyclopedia) Turner, Tina 1939- , African American R&B and rock singer, b. Brownsville, Tn., as Anna Mae Bullock. Turner had a turbulent childhood, with her par...

tyrosine

(Encyclopedia)CE5 tyrosine tīˈrəsēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. It is not essential to the huma...

United Nations Conference on Environment and Development

(Encyclopedia)United Nations Conference on Environment and Development (UNCED) or Earth Summit, an 11-day meeting held in June, 1992, in Rio de Janeiro, Brazil, to discuss the global conflict between economic devel...

hydroxide

(Encyclopedia)hydroxide hīdrŏkˈsīd [key], chemical compound that contains the hydroxyl (−OH) radical. The term refers especially to inorganic compounds. Organic compounds that have the hydroxyl radical as a f...