Match the carbohydrates in Column I with the correct glycosidic linkages involved in Column II.
Column I: P. Amylose; Q. Sucrose; R. Amylopectin; S. Cellulose.
Column II: 1. β (1→4); 2. α (1→4); 3. α1→β2; 4. α (1→4), α (1→6).
P-4; Q-3; R-2; S-1
P-2; Q-1; R-4; S-3
P-2; Q-3; R-4; S-1
P-1; Q-3; R-4; S-2
ANSWER
The correct matching is P-2; Q-3; R-4; S-1, which is option C.
Official answer: CSource: Official answer key, GATE 2026 BT (IIT Guwahati)
P, Amylose: an unbranched chain of glucose units joined only by bonds, so P matches 2.
Q, Sucrose: a disaccharide of glucose and fructose joined through both anomeric carbons, , written , so Q matches 3.
R, Amylopectin: a branched starch. The main chain is and the branch points are (about one in 24 to 30 residues), so R matches 4.
S, Cellulose: glucose units joined by bonds. Each residue is flipped relative to the next, giving straight chains that hydrogen-bond into fibres, so S matches 1.
The matching is P-2; Q-3; R-4; S-1.
Option A gives amylose the branched linkage 4 and amylopectin 2, so it is wrong. Option B pairs sucrose with 1 and cellulose with 3, so it is wrong. Option D pairs amylose with the linkage and cellulose with 2, so it is wrong. Only option C matches all four.
KEY IDEA
Starch is amylose ( only) plus amylopectin ( with branches). Cellulose is . Sucrose is the odd one out, with a glycosidic bond that links the two anomeric carbons, .
WATCH OUT FOR
Giving cellulose the linkage, or amylose the branched linkage. Only amylopectin has the branch points.
From the GATE 2026 BT paper. Every question of this paper · Download the full paper · All 12 Biomolecules questions, with notes
