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rosin

(Encyclopedia)rosin or colophony, hard, brittle, translucent resin, obtained as a solid residue from crude turpentine. Usually pale yellow or amber, its color may vary from brownish-black to transparent depending o...

cysteine

(Encyclopedia)CE5 CE5 cysteine sĭsˈtēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of mammalian protein...

copper, chemical element

(Encyclopedia)copper, metallic chemical element; symbol Cu [Lat. cuprum=copper]; at. no. 29; at. wt. 63.546; m.p. 1,083.4℃; b.p. 2,567℃; sp. gr. 8.96 at 20℃; valence +1 or +2. Copper and some of its alloys ha...

enzyme

(Encyclopedia)enzyme, biological catalyst. The term enzyme comes from zymosis, the Greek word for fermentation, a process accomplished by yeast cells and long known to the brewing industry, which occupied the atten...

indigo

(Encyclopedia)indigo [Span.; from Lat.,=Indian], important blue dyestuff used in printing inks and for vat dyeing of cotton (see dye). It was anciently produced in India and was known in Egypt, probably c.1600 b.c....

nitrocellulose

(Encyclopedia)nitrocellulose, nitric acid ester of cellulose (a glucose polymer). It is usually formed by the action of a mixture of nitric and sulfuric acids on purified cotton or wood pulp. The extent of nitratio...

perfluoroalkyl and polyfluoroalkyl substances

(Encyclopedia)perfluoroalkyl and polyfluoroalkyl substances (PFAS), a group of several thousand synthetic organic chemical compounds made up of a chain of carbon atoms bonded to fluorine atoms. PFAS, which resist w...

Lindahl, Tomas

(Encyclopedia)Lindahl, Tomas, 1938–, Swedish-born British biochemist, grad. Karolinska Institute (Ph.D. 1967, M.D. 1970). Lindahl was a professor at the Univ. of Gothenburg from 1978 to 1982. In 1981 he joined th...

Khorana, Har Gobind

(Encyclopedia)Khorana, Har Gobind, 1922–2011, American biochemist, b. Raipur (now in Pakistan), Ph.D. Univ. of Liverpool, 1948. He became a U.S. citizen in 1966, and was a professor at the Massachusetts Institute...

benzaldehyde

(Encyclopedia)benzaldehyde bĕnˌzēnkärˈbənəl [key], C6H5CHO, colorless liquid aldehyde with a characteristic almond odor. It boils at 180℃, is soluble in ethanol, but is insoluble in water. It is formed by ...