Question

Main component of fungal cell wall is-
a. Cellulose
b. Chitin
c. Pectin
d. Dextrin

Answer 1

Hint: A long-chain N-acetylglucosamine polymer, a glucose derivative. A primary component of fungal cell walls, arthropod exoskeletons such as crustaceans and insects, radulae of molluscs, beaks of cephalopods, and scales of fish and lissamphibians is this polysaccharide.

Complete answer:
> Option A is incorrect. Cellulose is a molecule composed of hundreds of carbon, hydrogen and oxygen atoms, and occasionally even thousands of them. In the walls of plant cells, cellulose is the main material, allowing plants to stay rigid and upright. Cellulose cannot be digested by humans, but it is as essential as fibre in the diet.

> Option B is correct. Cell walls made of the N-acetylglucosamine polymer chitin are owned by fungal cells. Chitin provides the thin cell walls of the fungus with rigidity and structural support, and makes fresh mushrooms crisp. Chitin is a polysaccharide that helps plants and animals to penetrate the long, fibrous cell walls of the fungus to break them down and extract nutrients.

> Option C is incorrect. Pectin occurs naturally in plants. It mainly resides in the walls of plant cells and helps tie cells together. There are more pectin-rich fruits and vegetables than others. This is a soluble fibre known as a polysaccharide, a long, indigestible sugar chain. Pectin expands and transforms into a gel when heated in the presence of fluid, making it a perfect thickener for jams and jellies.

> Option D is incorrect. Dextrins are a group of low molecular weight carbohydrates that are formed by starch or glycogen hydrolysis. Dextrins are blends of D-glucose unit polymers connected by glycosidic bonds of $\alpha -(1\to 4)$ or $\alpha -(1\to 6)$. Dextrins can be produced from almost any source of starch, such as maize, wheat or potatoes.

Hence, the correct answer is option (B).

Note: Chitin has the monomer hydroxyl group replaced with an acetyl amine group. The resulting stronger hydrogen bond between the bordering polymers makes chitin, like glucose and cellulose, harder and more stable than cellulose.