CARBOHYDRATES 1 1 7 



then fermented by the alcohol producing enzyme zymase, and 

 alcohol results, 



C12H22O11 + sucrase + H2O -> 2 C6H12O6 



Hydrolysis. — When sucrose is hydrolyzed by enzymes or 

 by boiling with acids, it yields two molecules of monosaccharoses. 

 One molecule, however, is dextro-rotatory glucose and the other 

 is levo-rotatory fructose. 



C12H22O11 + H2O — > CeHisOe + C6H12O6 



Cane sugar Glucose Fructose 



Inversion. — As fructose is more strongly levo-rotatory 

 than glucose is dextro-rotatory, a mixture of equal molecules of 

 each is not inactive like equal molecules of dextro and levo 

 lactic acid or tartaric acid, but is levo-rotatory. As the su- 

 crose itself is dextro-rotatory, the hydrolysis thus changes or 

 inverts the solution as to the direction in which it rotates the 

 plane of polarized light. The process of converting sucrose into 

 a mixture of glucose and fructose is, therefore, known as inver- 

 sion, and the mixture of glucose and fructose obtained is called 

 invert sugar. Invert sugar then is the mixture of equal mole- 

 cules of glucose and fructose obtained by the hydrolysis or 

 inversion of sucrose. 



C12H22O11 + H2O — > C6H12O6 + C6H12O6 



Sucrose Hydrolysis Glucose Fructose 



Dextro- or Dextro- Levo- 



rotatory Inversion rotatory rotatory 



. . » 



Invert sugar, levo-rotatory 



The similar hydrolysis of the other disaccharoses, maltose 

 and lactose, yields products of the same direction of optical 

 rotation. These hydrolyses do not, therefore, result in inver- 

 sion. 



Invert Sugar. — Invert sugar may be separated by crystal- 

 lization into the more readily crystallized glucose and the less 



