Skip to main content
Back

Introduction to Bacterial Cell Walls definitions

Control buttons has been changed to "navigation" mode.
1/15
  • Cell Wall
    Semi-rigid outer layer of bacteria that prevents rupture from internal water pressure and provides structural support.
  • Peptidoglycan
    Mesh-like polymer of polysaccharides and proteins unique to bacteria, forming the main structural component of the cell wall.
  • Cell Envelope
    Collective term for all layers surrounding a bacterial cell, including the cell wall, cell membrane, and outer membrane if present.
  • N-acetylglucosamine
    Monosaccharide subunit, abbreviated as NAG, that alternates with NAM in glycan chains of peptidoglycan.
  • N-acetylmuramic Acid
    Monosaccharide subunit, abbreviated as NAM, found in peptidoglycan and linked to tetrapeptide chains.
  • Glycan Chain
    Long sugar chain in peptidoglycan, composed of alternating NAG and NAM units linked by beta-1,4-glycosidic bonds.
  • Tetrapeptide
    Short peptide of four amino acids attached to NAM units, crucial for cross-linking glycan chains in peptidoglycan.
  • Peptide Interbridge
    Amino acid cross-link connecting tetrapeptides of adjacent glycan chains, present in gram-positive bacteria.
  • Gram Stain
    Differential staining technique that distinguishes bacteria based on cell wall structure, resulting in purple or colorless cells.
  • Gram-Positive Bacteria
    Bacteria with thick peptidoglycan layers, lacking an outer membrane, and retaining the purple Gram stain.
  • Gram-Negative Bacteria
    Bacteria with thin peptidoglycan layers, possessing an outer membrane, and not retaining the purple Gram stain.
  • Outer Membrane
    Additional membrane external to the cell wall in gram-negative bacteria, contributing to structural complexity.
  • Capsule
    Optional outermost layer in some bacteria, outside the cell envelope, providing extra protection and sometimes aiding in adherence.
  • Beta-1,4-Glycosidic Bond
    Covalent linkage joining NAG and NAM units in glycan chains, essential for peptidoglycan stability.
  • Plasma Membrane
    Innermost membrane of bacterial cells, also called the cell membrane, forming part of the cell envelope.