Question

Glucose is a
a. Cane sugar
b. Grape sugar
c. Malt sugar
d. Triose sugar

Answer 1

There are three major size classes of carbohydrates, namely monosaccharides (contain a single polyhydroxy aldehyde or ketone unit), oligosaccharides (contain short chains of monosaccharide units joined by glycosidic linkages), and polysaccharides (contain more than 20 to hundreds or thousands of monosaccharide units).

Complete answer:
- Glucose is a monosaccharide hexose sugar with the molecular formula C6H12O6. It is an aldohexose because it contains an aldehyde group. It is a product of almost all the photosynthetic processes. Glucose occurs naturally and is also found in fruits and other plant parts in its free state. For eg. Grapes contain grape sugar whose major content is glucose, often referred to as dextrose and also fructose (fruit sugar).
- Cane sugar is obtained from sugarcane, belonging to the Poaceae family. It consists of sucrose, a disaccharide. It is composed of two monosaccharides, namely glucose and fructose, joined together by a glycosidic linkage between C1 of the glucosyl subunit and C2 on the fructosyl subunit.
- Malt sugar is basically maltose. A disaccharide formed by two glucose units joined together by an α bond. When β-amylase is breaking down starch, two units of glucose are removed at a time, producing maltose.
- Triose sugar is basically a three-carbon sugar, most commonly known as glyceraldehyde (an aldotriose) or dihydroxyacetone (a ketotriose).

Hence, the correct answer is option (B).

Note: The property of sugar to rotate a beam of light when it passes through it classifies them into two classes, dextrorotatory and laevorotatory. These are usually represented by a (+) and a (-) sign.