20. Carbohydrates

Lactulose represents a man-made disaccharide that possesses a b-1,4 glycosidic linkage. Determine the two monosaccharide units created from its hydrolysis.

Refer to the cellobiose structure in Worked Example 20.5. How would you classify the link between the monosaccharides in cellobiose?

Consider the trisaccharide A, B, C shown in Problem 20.23.

a. Identify the hemiacetal and acetal linkages.

Consider the trisaccharide A, B, C shown in Problem 20.23.

c. State the numbers of the carbon atoms that form glycosidic linkages between monosaccharide A and monosaccharide B.

Look at the open-chain form of d-mannose (Problem 20.50) and draw the two glycosidic products that you expect to obtain by reacting d-mannose with methanol.

For each of the following disaccharides, name the glycosidic bond and draw the monosaccharide units produced by hydrolysis: (a) <IMAGE>

Draw the product of the following 1→4 condensation and name the glycosidic bond: 

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Identify the following reactions as condensation or hydrolysis:

(a) two monosaccharides reacting to form a disaccharide

Name the glycosidic bond present in mannobiose, shown in the following figure:

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Mannobiose

Write the molecular formula for a carbohydrate containing three carbons.