Difference between cell wall and cell membrane
The cell membrane and cell wall are two different layers that surround a cell.1 While all living cells have a cell membrane, only certain organisms (like plants, fungi, and bacteria) have a cell wall.2
A helpful way to visualize this is to think of a house: the cell membrane is like the inner dry-wall and security system that controls who enters, while the cell wall is the heavy brick or stone exterior that keeps the house from collapsing.3
Key Differences
Feature | Cell Membrane (Plasma Membrane) | Cell Wall |
Presence | Found in all living cells (animals, plants, etc.). | Found only in plants, fungi, and bacteria. |
Location | Outermost layer in animal cells; inside the wall in plants. | The outermost layer, surrounding the cell membrane. |
Texture | Thin, delicate, and flexible. | Thick, tough, and rigid. |
Permeability | Selectively Permeable (acts as a gatekeeper). | Generally Permeable (allows most substances to pass). |
Composition | Made of lipids and proteins. | Made of cellulose (plants), chitin (fungi), or peptidoglycan (bacteria). |
Function | Regulates entry/exit of materials; communication. | Provides structural support, shape, and protection.4 |
Structural Comparison
Selectivity: The cell membrane is "selectively permeable," meaning it actively chooses which nutrients come in and which waste products leave.5 The cell wall is more like a porous mesh; it provides strength but isn't as picky about what molecules float through it.6
Rigidity: Because animal cells lack a cell wall, they are squishy and can change shape.7 Plant cells are rigid because of their cell walls, which allows plants to grow tall without having a skeleton.
Metabolism: The cell membrane is metabolically active, meaning it is a "living" part of the cell that responds to its environment.8 The cell wall is generally considered non-living and metabolically inactive once it is fully formed.9