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Metonic cycle

(Encyclopedia)Metonic cycle: see synodic period. ...

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...

Passion cycle

(Encyclopedia)Passion cycle, in art, the depiction of the last events in the life of Jesus. The Passion was a favorite subject of medieval and Renaissance artists and was considered the most ambitious of projects. ...

Ulster cycle

(Encyclopedia)Ulster cycle: see Gaelic literature. ...

carbon cycle

(Encyclopedia)CE5 Carbon cycle carbon cycle, in biology, the exchange of carbon between living organisms and the nonliving environment. Inorganic carbon dioxide in the atmosphere is converted by plants into sim...

Krebs, Edwin Gerhard

(Encyclopedia)Krebs, Edwin Gerhard, 1918–2009, American biochemist, b. Lansing, Iowa. He and fellow Univ. of Washington professor Edmond Fischer discovered a biological regulatory mechanism, reversible protein ph...

proton-proton cycle

(Encyclopedia)proton-proton cycle: see nucleosynthesis. ...

Fischer, Edmond Henri

(Encyclopedia)Fischer, Edmond Henri, 1920–, American biochemist, b. Shanghai, China. As researchers at the Univ. of Washington in Seattle, Fischer and Edwin G. Krebs discovered a biological regulatory mechanism, ...

carbon-nitrogen-oxygen cycle

(Encyclopedia)carbon-nitrogen-oxygen cycle: see nucleosynthesis. ...

laetrile

(Encyclopedia)laetrile lāˈətrĭlˌ [key], name given to the chemical amygdalin, a substance derived from an extract of the kernels of many fruits, notably apricots, bitter almonds, and peaches. The idea that lae...