Which of the following is a straight chain polysaccharide composed only of β-D-glucose units?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Cellulose
Polysaccharides differ in the kind of glucose unit, the glycosidic linkage and the branching. Cellulose is the one made only of β-D-glucose units in unbranched chains; the chains lie side by side and are held together by hydrogen bonds, which makes cellulose strong and insoluble in water. Starch and glycogen, by contrast, are polymers of α-D-glucose and are branched (amylopectin, glycogen).
NCERT (2026-27 edition):
Polysaccharides – …
