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urea

(Encyclopedia)CE5 urea yo͝oēˈə [key], organic compound that is the principal end product of nitrogen metabolism in most mammals. Urea was the first animal metabolite to be isolated in crystalline form; its c...

Agriculture, United States Department of

(Encyclopedia)Agriculture, United States Department of, federal executive department established in 1862, whose head was made a cabinet member in 1889. The department administers federal programs related to food pr...

nitrogen cycle

(Encyclopedia)CE5 Nitrogen cycle nitrogen cycle, the continuous flow of nitrogen through the biosphere by the processes of nitrogen fixation, ammonification (decay), nitrification, and denitrification. Nitrogen...

Hofmann, August Wilhelm von

(Encyclopedia)Hofmann, August Wilhelm von ouˈgo͝ost vĭlˈhĕlm fən hôfˈmän [key], 1818–92, German organic chemist. He was professor at the Univ. of Berlin from 1865 and was a founder (1868) of the German C...

Prelog, Vladimir

(Encyclopedia)Prelog, Vladimir vlädyēˈmĭr prāˈlôg [key], 1906–98, Swiss chemist, b. Sarejevo, Austria-Hungary (now in Bosnia and Herzegovina). Educated in Prague, he worked in Yugoslavia until the German i...

phenolphthalein

(Encyclopedia)phenolphthalein fēˈnôlthălˈēən [key], or 2,2-Bis(p-hydroxyphenyl) phthalide, C20H14O4, crystalline organic compound. It is used medicinally as a laxative and is widely employed in the laborator...

world soul

(Encyclopedia)world soul, Lat. anima mundi, in philosophy, term denoting a universal spirit or soul that functions as an organizing principle. While many early Greek philosophers saw the world as of one principle, ...

Fungi

(Encyclopedia)Fungi fŭnˈjī [key], kingdom of heterotrophic single-celled, multinucleated, or multicellular organisms, including yeasts, molds, and mushrooms. The organisms live as parasites, symbionts, or saprob...

chemistry

(Encyclopedia)chemistry, branch of science concerned with the properties, composition, and structure of substances and the changes they undergo when they combine or react under specified conditions. Organic chemi...

stomach

(Encyclopedia)stomach, saclike dilation in the gastrointestinal tract between the esophagus and the intestines, forming an organ of digestion. The stomach is present in virtually all vertebrate animals and in many ...