(4)

Fructose is found in honey, contains keto group, exists in $\mathrm{\alpha }$- and $\mathrm{\beta }$-anomeric forms.
It is a laevorotatory compound hence, sugar ‘X’ is D(–)fructose.

(2)

Chemically, amylose is a long unbranched chain with 200–1000 $\mathrm{\alpha }$-D-(+)-glucose units held together by ${\mathrm{C}}_1–{\mathrm{C}}_4$ glycosidic linkage. Structure of glycogen is similar to amylopectin as it is a branched chain polymer of $\mathrm{\alpha }$-D-glucose units in which chain is formed by ${\mathrm{C}}_1–{\mathrm{C}}_4$ glycosidic linkage whereas branching occurs by ${\mathrm{C}}_1–{\mathrm{C}}_6$ glycosidic linkage.

(3)

Despite having the aldehyde group, glucose does not react with Schiff’s reagent and does not form the hydrogen sulphite addition product with ${\mathrm{NaHSO}}_3$.

(3)

In sucrose, two monosaccharides are held together by a glycosidic linkage between C-1 of $\mathrm{\alpha }$-D-glucose and C-2 of $\mathrm{\beta }$-D-fructose.

$\text{Sucrose}\stackrel{\text{Hydrolysis}}{\to }\alpha \text{-D-glucose}+\beta \text{-D-fructose}$

(4)

[IMAGE 341]

(2)

All monosaccharides whether aldoses or ketoses are reducing sugars. Disaccharides such as sucrose in which the two monosaccharide units are linked through their reducing centres. Sucrose is non-reducing because the reducing group of glucose and fructose are involved in glycosidic bond formation.

(4)

[IMAGE 346]