glyceride occurring naturally in animal and vegetable tissues; it consists of three individual fatty acids bound together in a single large molecule; an important energy source forming much of the fat stored by the body
an unsaturated fatty acid whose carbon chain has more than one double or triple valence bond per molecule; found chiefly in fish and corn and soybean oil and safflower oil
a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water)
a light silver-white ductile bivalent metallic element; in pure form it burns with brilliant white flame; occurs naturally only in combination (as in magnesite and dolomite and carnallite and spinel and olivine)
a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells; is highly reactive and occurs in several allotropic forms
a light soft silver-white metallic element of the alkali metal group; oxidizes rapidly in air and reacts violently with water; is abundant in nature in combined forms occurring in sea water and in carnallite and kainite and sylvite
a silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt)
a nonmetallic element belonging to the halogens; used especially in medicine and photography and in dyes; occurs naturally only in combination in small quantities (as in sea water or rocks)
a toxic nonmetallic element related to sulfur and tellurium; occurs in several allotropic forms; a stable grey metallike allotrope conducts electricity better in the light than in the dark and is used in photocells; occurs in sulfide ores (as pyrite)
a bluish-white lustrous metallic element; brittle at ordinary temperatures but malleable when heated; used in a wide variety of alloys and in galvanizing iron; it occurs naturally as zinc sulphide in zinc blende
(microbiology) an infectious protein particle similar to a virus but lacking nucleic acid; thought to be the agent responsible for scrapie and other degenerative diseases of the nervous system