Which carbohydrate forms the cell walls of bacteria?

Which carbohydrate forms the cell walls of bacteria?

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

Answer: (C)

Peptidoglycan forms the cell walls of bacteria. It is a rigid, mesh-like polymer built from alternating sugar units—N-acetylglucosamine and N-acetylmuramic acid—cross-linked by short peptide chains. This lattice gives bacteria their shape and protects them from bursting in hypoosmotic environments. Chitin is found in fungal cell walls and some arthropod exoskeletons, cellulose in plant cell walls, and lignin is a plant polymer; none of these form bacterial cell walls. Some bacteria lack cell walls, but those that do rely on peptidoglycan for structure.

Peptidoglycan forms the cell walls of bacteria. It is a rigid, mesh-like polymer built from alternating sugar units—N-acetylglucosamine and N-acetylmuramic acid—cross-linked by short peptide chains. This lattice gives bacteria their shape and protects them from bursting in hypoosmotic environments. Chitin is found in fungal cell walls and some arthropod exoskeletons, cellulose in plant cell walls, and lignin is a plant polymer; none of these form bacterial cell walls. Some bacteria lack cell walls, but those that do rely on peptidoglycan for structure.