Simulation · Biology · Class 11
Layers of a plant cell wall
From the lesson Cell wall in Cell: The Unit of Life. Change the values and watch what happens.
Layers of a plant cell wallBiology · Class 11
The idea behind it
NCERT §8.5.2
- In plants and fungi a rigid, non-living cell wall covers the plasma membrane. Its jobs: giving the cell its shape, guarding against mechanical injury and infection, helping cells interact, and keeping out unwanted macromolecules.
- Algal walls are made of cellulose, galactans, mannans and minerals such as calcium carbonate.
- Walls of other plants contain cellulose, hemicellulose, pectins and proteins.
- A young plant cell has a primary wall that can grow; this growth gradually slows as the cell matures.
- The secondary wall is laid down on the inner side of the primary wall, that is, towards the plasma membrane.
- The middle lamella, made mainly of calcium pectate, is the layer that glues neighbouring cells together.
- Going outward from the cell: plasma membrane, secondary wall, primary wall, middle lamella. Plasmodesmata pass through the wall and middle lamella to join the cytoplasm of adjacent cells.