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Difficulty: MediumKingdom Monera: Bacteria and Cyanobacteria

Which chemical constituent forms the main structural meshwork of bacterial cell walls, maintaining cellular rigidity and protecting prokaryotes from osmotic lysis?

  1. PeptidoglycanAnswer
  2. B
    Cellulose
  3. C
    Chitin
  4. D
    Protein capsid

Answer

Peptidoglycan forms the primary structural meshwork of bacterial cell walls.
Peptidoglycan (also called murein) consists of repeating disaccharide units cross-linked by short peptide chains. It surrounds the bacterial plasma membrane, imparting mechanical strength, maintaining shape, and safeguarding the bacterium against osmotic lysis.

Step-by-Step Solution

1
Identify the cellular organization and kingdom of bacteria.
Bacteria belong to Kingdom Monera and are single-celled prokaryotes possessing a rigid cell wall.
Determining kingdom-specific cell wall polymers helps differentiate prokaryotic walls from eukaryotic walls.
2
Evaluate the chemical composition of prokaryotic cell walls versus other organisms.
Bacteria synthesize peptidoglycan (murein), whereas plants synthesize cellulose and fungi synthesize chitin.
Peptidoglycan provides the tensile strength necessary to resist internal osmotic pressure and prevent bursting.

Key Concept

Bacterial Cell Wall Composition
Estimated Time:1m 0s
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Topics

Kingdom Monera: Bacteria and Cyanobacteria

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