1.2 Cell wall
The materials of the plant cell wall are initially deposited on the surface of the middle lamella. This primary cell wall occurs on the surface of all plant cells, outside of the cell membrane. It is substantially composed of cellulose molecules that are bundled together to form fibrils.
The primary cell wall is the only cell wall present in some cells.
In other cells a secondary cell wall is deposited inside the primary cell wall. This secondary cell wall may contain lignin. Lignin makes the cell wall rigid and stronger.
The cell membrane lies immediately adjacent to the cell wall, on the interior surface, and surrounds the contents of the cell.
To allow communication between cells there are membrane lined pores, or plasmodesmata, which run through the cell walls.
Media Attributions
- Figure 1.3. Diagrammatic structure of a primary cell wall (top) next to a secondary cell wall (lower left) and a primary cell wall (lower right) © Sean Bellairs is licensed under a CC BY-SA (Attribution ShareAlike) license
- Figure 1.4. Plasmodesmata passing through the cell wall in a TEM of a Coleus blumei shoot apex © Louisa Howard, Charles Daghlian is licensed under a Public Domain license
- Figure 1.5. Diagram of a plasmodesmata connection between two cells © Zlir'a adapted by Kelvin Ma is licensed under a Public Domain license