sugar substitute: see sweetener, artificial.

sugar of lead: see lead acetate.

sugar maple: see maple.

sugar beet, variety of beet used commercially as a source of sugar.

sugar, compound of carbon, hydrogen, and oxygen belonging to a class of substances called carbohydrates. Sugars fall into three groups: the monosaccharides, disaccharides, and trisaccharides. The monosaccharides are the simple sugars; they include fructose and glucose. The disaccharides are formed by the union of two monosaccharides with the loss of one molecule of water. Disaccharides include lactose, maltose, and sucrose. Less well known are the trisaccharides; raffinose is a trisaccharide present in cottonseed and in sugar beets. Sugars belong to two families denoted by the letter d- or l- written before the name of a sugar. The families are related to glyceraldehyde CH₂OHCHOHCHO, which can exist in two three-dimensional forms that are mirror images of each other. The isomer of glyceraldehyde that rotates plane polarized light clockwise is labeled d-glyceraldehyde; all natural sugars can be derived from this substance and thus belong the the d family. Although l-sugars can be prepared in the laboratory, they cannot be utilized by animals.

milk sugar: see lactose.

grape sugar: see glucose.

fruit sugar: see fructose.

cane sugar: see sucrose.

beet sugar: see beet; sucrose.

Sugar Land, city (2000 pop. 63,328), Fort Bend co., SE Texas, on the Brazos River and Oyster Creek, a W suburb of Houston; inc. 1959. The city, which now has a diversified economy, began as a pre-Civil War sugar plantation and was a sugar refining center until 2003; Imperial Sugar's headquarters are still there. A satellite campus of the Univ. of Houston and a Southern history museum are in Sugar Land.

Robinson, Sugar Ray, 1920-89, American boxer, b. Detroit. His real name was Walker Smith. He began boxing after three years of high school in New York City. Having won all his amateur fights (about 90), including the Golden Gloves featherweight title, Robinson turned professional in 1940. He won the welterweight championship in 1946 by defeating Tommy Bell and the middleweight championship for the first time in 1951 by knocking out Jake La Motta. When Robinson retired from boxing as middleweight champion in 1952 he had lost only three times in 137 bouts. Returning to boxing in 1955, he was the first boxer ever to regain a title after retiring. Robinson became the first man in boxing history to win a divisional (weight class) world championship five times when he regained the middleweight title in 1958 by defeating Carmen Basilio; he lost the title in 1960 to Paul Pender. In his prime, the swift, hard-punching Robinson was rated the best boxer, pound for pound, of his time.

Any of numerous sweet, colourless organic compounds that dissolve readily in water and occur in the sap of seed plants and the milk of mammals. Sugars (whose names end in -ose) are the simplest carbohydrates. The most common is sucrose, a disaccharide; there are numerous others, including glucose and fructose (both monosaccharides); invert sugar (a 50:50 mixture of glucose and fructose produced by enzyme action on sucrose); and maltose (produced in the malting of barley) and lactose (both disaccharides). Commercial production of sugars is almost entirely for food.

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Any of the simple sugars that serve as building blocks for carbohydrates. They are classified based on their backbone of carbon (C) atoms: Trioses have three carbon atoms, tetroses four, pentoses five, hexoses six, and heptoses seven. The carbon atoms are bonded to hydrogen atoms (singlehorzbondH), hydroxyl groups (singlehorzbondOH; see functional group), and carbonyl groups (singlehorzbondCdoublehorzbondO), whose combinations, order, and configurations allow a large number of stereoisomers (see isomer) to exist. Pentoses include xylose, found in woody materials; arabinose, found in gums from conifers; ribose, a component of RNA and several vitamins; and deoxyribose, a component of DNA. Important hexoses include glucose, galactose, and fructose. Monosaccharides combine with each other and other groups to form a variety of disaccharides, polysaccharides, and other carbohydrates.

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Slightly sweet sugar (disaccharide) composed of two monosaccharides, glucose and galactose, linked together. Lactose-intolerant adults, and more rarely infants, cannot digest lactose because they lack the enzyme (lactase) that splits it into simpler sugars and suffer diarrhea and bloating when they eat foods containing it. Lactose, which makes up 2–8percnt of the milk of mammals, is the only common sugar of animal origin. Commercial lactose is obtained from whey, a liquid by-product of cheese. It is used in foods, in pharmaceuticals, and in nutrient broths used to produce penicillin, yeast, and riboflavin, and other products.

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or dextrose or grape sugar or corn sugar

Organic compound, a simple sugar (monosaccharide), chemical formula C₆H₁₂O₆. The product of photosynthesis in plants, it is found in fruits and honey. As the major circulating free sugar in blood, it is the source of energy in cell function and a major participant in metabolism. Control of its level and metabolism is of great importance (see insulin). Glucose and fructose make up sucrose. Glucose units in long chains make up polysaccharides (e.g., cellulose, glycogen, starch). Glucose is used in foods, medicine, brewing, and wine making and as the source of various other organic chemicals.

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or levulose or fruit sugar

Organic compound, one of the simple sugars (monosaccharides), chemical formula C₆H₁₂O₆. It occurs in fruits, honey, syrups (especially corn syrup), and certain vegetables, usually along with its isomer glucose. Fructose and glucose are the components of the disaccharide sucrose (table sugar); hydrolysis of sucrose yields invert sugar, a 50:50 mixture of fructose and glucose. The sweetest of the common sugars, fructose is used in foods and medicines.

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orig. Walker Smith, Jr.

(born May 3, 1921, Detroit, Mich., U.S.—died April 12, 1989, Culver City, Calif.) U.S. boxer. Robinson began boxing in high school in New York City and won all of his 89 amateur fights. He was six times a world champion, once (1946–51) as a welterweight (147 lbs) and five times (1951–60) as a middleweight (160 lbs). In 201 professional bouts, he made 109 knockouts. He suffered only 19 defeats, most when he was past 40. His outstanding ability and flamboyant personality made him a hero of boxing fans throughout the world, and he is sometimes considered the best fighter in history.

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