Question

Describe how the structure of sucrose differs from that of erlose.

Answer 1

Sucrose is a disaccharide made of glucose and fructose with an a-1,β-2-glycosidic linkage, while erlose is a trisaccharide with additional glucose and different glycosidic bonds.

Step-by-step explanation:

The structure of sucrose differs from that of erlose in terms of molecular composition and the specific bond formation between the monosaccharides. Sucrose is a disaccharide made up of one molecule of D-glucose (in pyranose form) and one molecule of D-fructose (in furanose form), connected by an a-1,β-2-glycosidic linkage. This means that the glucose and fructose in sucrose are linked through their anomeric carbons; the carbon-1 of glucose and carbon-2 of fructose, respectively. Erlose, on the other hand, is a trisaccharide consisting of three monosaccharide units: two glucose molecules and one fructose molecule.

The structural complexity of erlose is increased due to the presence of an additional glucose unit compared to sucrose. Furthermore, the pattern of glycosidic linkages would be different in erlose, involving a series of α and β bonds, depending on the specific orientation of the hydroxyl groups on the glucose and fructose units. While the empirical formulas of these sugars may be similar, delineating their structures through molecular weights and glycosidic bonds is crucial for understanding their biochemical properties and reactivity.

Answer 2

Sucrose is a disaccharide. It has the chemical formula C12H22O11. Its structure is composed of one glucose and one fructose joined at the glucosyl C1 to the fructosyl C2 by an ether bridge.

Erlose is a trisaccharide, composed of two glucosyls and one fructosyl subunit. Erlose can be formed from sucrose and glucose by joining the glucose C1 to the C4 of the glucosyl subunit of glucose by an ether bridge.