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cellophane

(Encyclopedia)cellophane, thin, transparent sheet or tube of regenerated cellulose. Cellophane is used in packaging and as a membrane for dialysis. It is sometimes dyed and can be moisture-proofed by a thin coating...

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...

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...

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...

topaz

(Encyclopedia)topaz tōˈpăz [key], aluminum silicate mineral with either hydroxyl radicals or fluorine, Al2SiO4(F,OH)2, used as a gem. It is commonly colorless or some shade of pale yellow to wine-yellow; pale bl...

urine

(Encyclopedia)urine, clear, amber-colored fluid formed by the kidneys that carries metabolic wastes out of the body (see urinary system). As the blood circulates it collects excretory products from the tissues and ...

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....

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...