Question

The bacterial cell wall is predominantly made up of

• A. Only protein
• B. Lipoprotein
• C. Glycoprotein
• D. Only lipid

Hint:

Bacterial Cell Wall: Peptidoglycan (Murein) = Glycan backbone (NAG + NAM) cross-linked by oligopeptides (Glycopeptide/Glycoprotein matrix).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The structural integrity of eubacterial cell walls is provided by peptidoglycan (murein), a complex macromolecular heteropolymer composed of glycan strands cross-linked by short peptide chains (glycopeptide glycoprotein matrix).

Step 2: Detailed Explanation:
Bacterial cell walls consist predominantly of Peptidoglycan (Murein):
1. Glycan Component: Alternating copolymer of $\beta$-(1$\rightarrow$4) linked $N$-acetylglucosamine (NAG) and $N$-acetylmuramic acid (NAM).
2. Peptide Component: Short tetrapeptide side chains (L-Ala, D-Glu, $m$-DAP L-Lys, D-Ala) attached to NAM and cross-linked via pentaglycine bridges or direct transpeptidation.
Because of this covalent fusion of polysaccharide chains and peptide networks, it is chemically classified as a complex glycoprotein glycopeptide envelope.

Step 3: Final Answer:
Therefore, the bacterial cell wall is predominantly made up of Glycoprotein (peptidoglycan), corresponding to option (C).