Sucrose (Molecule of the Month for December 1996)
Complex Carbohydrates are made up of two or more simple sugars linked together. The following carbohydrates are disaccharides. Disaccharides are compounds that contain a bond between carbon(1) of one sugar and a hydroxyl group at any position on the other sugar.
Sucrose, ordinary table sugar, is probably the single most abundant pure organic chemical in the world and the one most widely known to nonchemists. Whether from sugar cane (20% by weight) or sugar beets (15% by weight), and whether raw or refined, common sugar is still sucrose.
Sucrose is a disaccharide that yields 1 equiv of glucose and 1 equiv of fructose on acidic hydrolysis. This 1:1 mixture of glucose and fructose is often referred to as invert sugar, since the sign of optical rotation changes (inverts) during the hydrolysis from sucrose ([alpha]D = +66.5o) to a glucose fructose mixture ([alpha]D = -22.0o). Certain insects, particularly honeybees, have enzymes called invertases that catalyze the hydrolysis of sucrose to a glucose-fructose mixture. Honey, in fact, is primarily a mixture of these three sugars.
Unlike most other disaccharides, sucrose is not a reducing sugar and does not exhibit mutarotation. These facts imply that sucrose has no hemiacetal linkages and that glucose and fructose must both be glycosides. This can happen only if the two sugars are joined by a glycoside link between C1 of glucose and C2 of fructose.
Formal Chemical Name (IUPAC)
Update by Karl Harrison
(Molecule of the Month for December 1996 )