JEE Main 2025 — Biomolecules Question with Solution

A) Amylose - Polysaccharide of glucose units with glycosidic linkage $\alpha -1,4$.

The source is plant.

So, the linkage is $\alpha -c_1-C_4$.

Glucose units in amylose are linked by alpha bonds between the $1^{\text{st }}$ and $4^{\text{th }}$ carbon atoms.

Amylose match with $\alpha -c_1-c_4$, plant

(A) with (IV)

B) Cellulose - The glycosidic linkage in cellulose is $\beta -1,4$. Glucose monomers are joined by linkage between the $c_1$ of the one glucose ling and the $C_4$ of the next ring.

Source is plant

Cellulose match with $\beta -C_1-C_4$, plant.

(B) with (I)

c) Glycogen - Glycogen is a polymer of glucose that is stored in animals as an energy reserve. It is used as carbohydrate storage in animals. It is a polymer of $\alpha$-glucose with $\alpha -1,4$-glycosidic and $\alpha -1,6$-glycosidic links.

$\alpha -1,4$-linkage forms during linear polymer.

$\alpha -1,6$ - linkage forms during the formation of branching.

Glycogen match with $\alpha -C_1-C_4$, animal

(C) with (II)

D) Amylopectin - It is the polymer of glucose units linked by $\alpha -1,4$ and $\alpha -1,6$ glycosidic bonds.

$x-1,4$ - glucose units linked in a linear way.

$\alpha -1,6$ - These bonds branch out from the linear chains of glucose units.

They are stored in large complexes called starch granules in plants.

Amylopectin match with $\alpha -c_1,c_4,\alpha -c_1-c_6$, plant (D) with (III).

Answer: $(A)-($ IV $),(B)-(I),(C)-($ II $),(D)-($ III $)$. Option (3).