Definition

1. Noun:
   • A rigid structural layer: A "cell wall" is a firm, non-living layer located outside the plasma membrane of certain cells. It provides structural support, defines the cell's shape, and acts as a protective barrier.
   • A defining feature of specific cell types: The presence of a "cell wall" is a key characteristic that distinguishes plant cells, algae, fungi, and most prokaryotic cells (like bacteria) from animal cells, which lack this structure.

Usage Examples

• Noun:
  • The plant's rigidity is due to the strong cellulose in its cell wall.
  • Scientists study the bacterial cell wall to develop new antibiotics.
  • Unlike animal cells, plant cells have a cell wall surrounding their membrane.

Advanced Usage

• "Cell wall composition": Refers to the specific chemical makeup of the wall, which varies between organisms (e.g., cellulose in plants, peptidoglycan in bacteria, chitin in fungi).
  • The cell wall composition of fungi is different from that of plants.
• "Cell wall integrity": Describes the state of the wall being intact and fully functional, which is crucial for cell survival.
  • The pathogen secretes enzymes that compromise the cell wall integrity of its host.

Variants and Related Words

• Cellulose (n): A complex carbohydrate (polysaccharide) that is the primary structural component of the plant cell wall.
• Peptidoglycan (n): A polymer that forms a mesh-like layer in the bacterial cell wall.
• Cell membrane / Plasma membrane (n): The flexible, living barrier inside the cell wall that controls the movement of substances in and out of the cell.

Synonyms

• Cellular envelope (less common, more technical)
• Extracellular matrix (in a broad, comparative sense for structural support outside the membrane, though this term is more general and used differently in animal biology)

Related Phrases

• Cell wall biosynthesis: The process by which a cell constructs its wall.
  • This antibiotic inhibits cell wall biosynthesis, causing the bacteria to burst.
• Cell wall degradation: The breakdown of the wall, often by enzymes.
  • The softening of fruit involves the gradual degradation of the cell wall.

Related Concepts

• Turgor pressure: The internal water pressure within a plant cell that pushes against the rigid cell wall, helping maintain the plant's upright structure.
  • When a plant wilts, it loses turgor pressure because water no longer presses firmly against the cell wall.
• Lysis: The rupture or disintegration of a cell. A compromised cell wall can lead to lysis.
  • Without its protective cell wall, the cell is susceptible to osmotic lysis.

Noun

1. a rigid layer of polysaccharides enclosing the membrane of plant and prokaryotic cells; maintains the shape of the cell and serves as a protective barrier