Glycosidic Bonds in Disaccharides Melibiose is a disaccharide that is 30 times sweeter than sucrose. a. What are the monosaccharide units in melibiose? b. What type of glycosidic bond links the monosaccharides? c. Identify the structure as α- or β-melibiose.

Question

Glycosidic Bonds in Disaccharides

Melibiose is a disaccharide that is 30 times sweeter than sucrose.

a. What are the monosaccharide units in melibiose?

b. What type of glycosidic bond links the monosaccharides?

c. Identify the structure as α- or β-melibiose.

Accepted Answer

ANALYZE THE PROBLEM	First Monosaccharide	When the ---OH group on carbon 4 is drawn above the
	(left)	plane, it is D-galactose.
		When the ---OH group on carbon 1 is drawn below the
		plane, it is the α isomer of D-galactose.
	Second Monosaccharide	When the ---OH group on carbon 4 is drawn below the
	(right)	plane, it is D-glucose.
	Type of Glycosidic Bond	The ---OH group at carbon 1 comes from α-D-galactose
		to the ---OH group on carbon 6 of glucose, which
		makes it an α-1,6-glycosidic bond.
	Position of Isomer ---OH	The ---OH group on carbon 1 of glucose is drawn below
	Group (right)	the plane, which is the α isomer of melibiose.
	Name of Disaccharide	α-melibiose

a. α-D-galactose and α-D-glucose

b. α-1,6-glycosidic bond

c. α-melibiose

Question 13.7: Glycosidic Bonds in Disaccharides Melibiose is a disaccharid...