CARBOHYDRATES 279 



about in the plant by enzymes, and artificially man brings it 

 about through the action of acids. Glucose is one of the products 

 obtained when cellulose and starch are decomposed. Commer- 

 cially, glucose is obtained from starch and chiefly from corn 

 starch. The annual production of glucose from starch in the 

 United States is about a billion pounds and the corn consumed 

 in this industry is about fifty million bushels. Glucose is much 

 used in making table sirups, vinegar, jams, jellies, artificial honey 

 and confectionery. 



Cane sugar (C^H^On) is the most important commercially. 

 It consists of a molecule of glucose plus a molecule of fructose 

 with a molecule of water dropped in the combination (C 6 H 12 O 6 

 +C 6 H 12 O 6 H 2 O=Ci2H 2 2Oii). Cane sugar occurs in most all 

 plants but is especially abundant in the sap of Sugar Cane, Sugar 

 Beets, Sorghum, and Maple trees. The yield of cane sugar runs 

 as high as 20 percent in Sugar Cane and Sugar Beets and 12 per- 

 cent or more in Sorghum. Maple sap contains from 1 to 3 per- 

 cent of cane sugar. In the tropical countries the sap of some 

 Palms is a source of cane sugar. It was estimated that the 

 world's production of cane sugar in 1906 was about 17 million 

 tons. Maltose, having the same formula as cane sugar but with 

 atoms differently arranged, occurs in jthe cell sap of leaves and 

 quite abundantly in germinating seeds, especially in those of the 

 cereals. Maltose results when starch is decomposed and such 

 is probably its origin in germinating seeds. Enzymes and hydro- 

 lytic acids and alkalies change it to glucose. 



As a food the sugars are important chiefly for the energy they 

 furnish. They are needed especially by workmen to furnish 

 muscular energy. Most individuals consume annually not far 

 from 100 Ibs. of sugar, and practically all of the energy of the 

 sugar can be liberated and used by the body. As a feed for live- 

 stock sugar is of considerable importance. Green pasture and 

 most feeds contain some sugar. In the South the liquor left in 

 the manufacture of sugar is used in the diet of mules and sugar 

 is used for fattening cattle. 



Starch (C 6 H 1 oO 5 )n is present in nearly all parts of plants. It 

 is most abundant in seeds, especially in those of the cereals where 

 in some cases it constitutes 70 percent of the dry weight. It 

 constitutes from a third to one-half or more of the dry weight of 

 the seeds of the Legumes, such as Beans, Peas, Peanuts, Soy 



