Question

Maltose is made of:
A) \[\alpha {\text{ - D - glucose}}\]
B) \[\alpha ,{\text{beta - D - glucose}}\]
C) Glucose and fructose
D) Fructose only

Answer 1

Hint: Maltose is also known as malt sugar. It is a disaccharide, made up of two D- glucose units. The two units of glucose are linked with an alpha 1,4 glycosidic bond.

Complete answer:
Maltose is a disaccharide made up of two alpha D- glucose in which C1 of the first glucose unit is bonded to C4 of the second glucose unit. The bond that joined two alpha glucose units is called 1, 4 glycosidic linkages.

The structure of maltose is as follows:

As maltose is made up of two alpha sugars so \[\alpha ,{\text{beta - D - glucose}}\]is an incorrect answer. Thus, option (B) \[\alpha ,{\text{beta - D - glucose}}\] is incorrect.

Maltose is made of two molecules of glucose while sucrose is made up of one molecule of glucose and one molecule of fructose. Thus, option (C) Glucose and fructose is an incorrect answer.

As monosaccharide of maltose is glucose, not fructose so option (D) Fructose only is incorrect.

Additional Information: Maltose is not used as a sweetener as it is less sweet. It is used to produce alcohol.

Thus, the correct answer is option (A) \[\alpha {\text{ - D - glucose}}\].

Note: The D- glucose exists in two forms alpha D -glucose and beta D- glucose. The difference between the two forms is the direction that H group and OH group point of C1. Depending on the type of monosaccharide there are different types of disaccharides. Maltose is reducing sugar. Monosaccharide of maltose is alpha D- glucose. Maltose is formed by alpha 1, 4 glycosidic linkage of two alpha D -glucose units.