Which carbohydrate forms the cell walls of plants?

Which carbohydrate forms the cell walls of plants?

• A. Lignin
• B. Cellulose
• C. Chitin
• D. Peptidoglycan

Answer: (B)

Cellulose is the carbohydrate that forms the plant cell wall. It consists of long chains of glucose linked by β-1,4 bonds, which bundle into strong cellulose microfibrils. These microfibrils are embedded in a matrix of other polysaccharides like hemicelluloses and pectins, creating a rigid yet flexible framework that supports the cell against internal pressure while allowing growth. In secondary walls, lignin adds extra stiffness, but it’s not a carbohydrate and doesn’t form the wall’s main carbohydrate framework. Chitin and peptidoglycan are polymers used in fungal/insect and bacterial cell walls, respectively, not in plants.

Cellulose is the carbohydrate that forms the plant cell wall. It consists of long chains of glucose linked by β-1,4 bonds, which bundle into strong cellulose microfibrils. These microfibrils are embedded in a matrix of other polysaccharides like hemicelluloses and pectins, creating a rigid yet flexible framework that supports the cell against internal pressure while allowing growth. In secondary walls, lignin adds extra stiffness, but it’s not a carbohydrate and doesn’t form the wall’s main carbohydrate framework. Chitin and peptidoglycan are polymers used in fungal/insect and bacterial cell walls, respectively, not in plants.