Question

Chitin is made up of
A. Polysaccharide
B. Nitrogenous polysaccharide
C. Lipoproteins
D. Protein

Answer 1

Hint:- Simple sugars are monomers for complex sugars. Complex sugars serve as a structural component of various cellular structures. Some of these biomolecules also serve as a storage molecule.

Complete step-by-step solution:-
Carbohydrates, proteins, lipids, and nucleic acids are the four main biomolecules present in the living cells. Proteins are the polymers of amino acids. Amino acids are bonded by peptide linkages to form the link chains of polypeptides. There are a total of 20 standard amino acids present in proteins. Each amino acid has a central carbon atom bonded to four different groups. These functional groups are the amino group, carboxyl group, side chain, and a hydrogen atom. Lipoproteins are the lipid droplets that are coated with proteins. Lipoproteins are mainly involved in the transport of digestion products of lipids.
Carbohydrates include monosaccharides, disaccharides, and polysaccharides. These compounds mainly have carbon, hydrogen, and oxygen atoms in their structures. Polysaccharides are the polymers of the simple sugars bonded together by glycosidic linkages. Simple sugars are the recurring units of the polysaccharides.
When a Polysaccharide is made up of a single type of monomer, it is called homopolysaccharide. Chitin is a homopolysaccharide that is composed of N-acetylglucosamine residues. The N-acetylglucosamine molecules are linked by a specific type of glycosidic linkage. N-acetylglucosamine is a derivative of glucose. The addition of the acetyl group to the nitrogen atom bonded to the glucose molecule forms N-acetylglucosamine. Therefore, chitin is a nitrogenous polysaccharide.
So, the correct answer is option B. Nitrogenous polysaccharide.

Note:- Chitin is the main component of fungal cell walls. It is also present in the exoskeletons of arthropods such as insects and crab. N-acetylglucosamine is a structural component of peptidoglycan which in turn makes the bacterial cell wall.