Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
A cell wall is a rigid layer that surrounds the cells of plants, fungi, bacteria, and archaea. It provides structural support and protection while also determining the shape of the cell.
5 Must Know Facts For Your Next Test
Plant cell walls are primarily composed of cellulose, hemicellulose, and lignin.
Bacterial cell walls contain peptidoglycan, which is essential for their structural integrity.
Archaea have unique cell wall compositions that lack peptidoglycan but may contain pseudopeptidoglycan or other polymers.
Fungal cell walls are made primarily of chitin.
The absence or presence of a cell wall helps differentiate between Gram-positive and Gram-negative bacteria through Gram staining.
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Related terms
Plasma Membrane: A selectively permeable barrier that encloses the cytoplasm of a cell, controlling movement in and out.
Peptidoglycan: A polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane in bacteria.
Chitin: A long-chain polymer derived from glucose found in fungal cell walls and exoskeletons of arthropods.