Q.43 Which of the following is/are heteropolysaccharide(s)?
(A) Chondroitin–4–sulfate
(B) Chitin
(C) Cellulose
(D) Heparin

Chondroitin-4-sulfate and Heparin are heteropolysaccharides. Heteropolysaccharides consist of two or more different monosaccharide units, unlike homopolysaccharides made from a single type. Thus, the correct answer is (A) and (D).​

Option Analysis

• (A) Chondroitin-4-sulfate: This glycosaminoglycan features repeating disaccharide units of glucuronic acid and N-acetylgalactosamine (with sulfate at position 4 on the latter), confirming its status as a heteropolysaccharide found in cartilage.​

• (B) Chitin: A homopolysaccharide composed entirely of N-acetylglucosamine units linked by β(1→4) bonds, forming structural components in fungal cell walls and arthropod exoskeletons.​

• (C) Cellulose: A homopolysaccharide of linear β(1→4)-linked D-glucose units, serving as the primary structural element in plant cell walls.​

• (D) Heparin: An anticoagulant heteropolysaccharide with repeating sulfated glucosamine and uronic acid (mainly iduronic acid) units, produced by mast cells.​

Heteropolysaccharides play key roles in biology, differing from homopolysaccharides by incorporating multiple monosaccharide types for diverse functions like anticoagulation and structural support. This guide analyzes options from CSIR NET-style questions on heteropolysaccharides examples such as Chondroitin-4-sulfate, Chitin, Cellulose, and Heparin, aiding exam preparation in biochemistry and molecular biology.​

Core Differences

Homopolysaccharides contain one monosaccharide (e.g., glucose in Cellulose), forming storage or rigid structures. Heteropolysaccharides blend units like glucosamine and uronic acids, enabling complex roles in extracellular matrices.​

Detailed Structures

• Chondroitin-4-sulfate: Repeating [-GlcA-β(1→3)-GalNAc4S-β(1→4)-] units; a sulfated glycosaminoglycan in connective tissues.​

• Chitin: β(1→4)-N-acetylglucosamine polymer; nitrogen-containing, second most abundant natural polysaccharide.​

• Cellulose: Linear β(1→4)-glucose chains; indigestible by humans but vital for herbivores.​

• Heparin: Highly sulfated [-IdoA(2S)-α(1→4)-GlcNS(6S)-α(1→4)-] repeats; enhances antithrombin activity.​

These insights align with CSIR NET Life Sciences syllabus on carbohydrate classification, emphasizing glycosidic linkages and biological significance.​