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mechanism

(Encyclopedia)mechanism, philosophical theory about the nature of organic systems, holding that organisms are machines in the sense that they are material systems. Mechanism seeks to explain biological processes, i...

ethyl

(Encyclopedia)ethyl ĕthˈəl [key], CH3CH2, organic free radical or alkyl group derived from ethane by removing one hydrogen atom. ...

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...

celestite

(Encyclopedia)celestite sĕlˈəstĭn, –tīn [key], mineral appearing in blue-tinged or white orthorhombic crystals or in fibrous masses. The natural sulfate of strontium, SrSO4, it is important as a source of st...

cerussite

(Encyclopedia)cerussite sērˈəsīt [key], colorless to white or gray mineral, sometimes yellowish or greenish, transparent to opaque, very brittle, crystallizing in the orthorhombic system and occurring also in g...

matter

(Encyclopedia)matter, anything that has mass and occupies space. Matter is sometimes called koinomatter (Gr. koinos=common) to distinguish it from antimatter, or matter composed of antiparticles. The atomic th...

Haskovo

(Encyclopedia)Haskovo khäsˈkōvōˌ [key], city, S Bulgaria, in an agricultural region noted for its tobacco. ...

ozone

(Encyclopedia)ozone ōˈzōn [key], an allotropic form of the chemical element oxygen (see allotropy). Pure ozone is an unstable, faintly bluish gas with a characteristic fresh, penetrating odor. The gas has a dens...

Mar, John Erskine, 2d (or 7th) earl of

(Encyclopedia)Mar, John Erskine, 2d (or 7th) earl of, 1558–1634, Scottish nobleman; son of the 1st (or 6th) earl. In 1578 he was persuaded by James Douglas, 4th earl of Morton, to assert his claims to Stirling Ca...

waterfowl

(Encyclopedia)waterfowl, common term for members of the order Anseriformes, wild, aquatic, typically freshwater birds including ducks, geese, and screamers. In Great Britain the term is also used to designate speci...