Here's why:
* Cell wall: The cell wall is a rigid outer layer in plant cells that provides support and protection. It also helps maintain the shape of the cell and prevents it from bursting due to osmotic pressure.
* Cell membrane: The cell membrane is a thin, flexible layer that surrounds all animal cells. While it doesn't provide the same level of rigidity as a cell wall, it plays a vital role in:
* Protection: It forms a barrier between the cell's interior and the external environment, protecting it from harmful substances.
* Regulation: It controls the movement of substances in and out of the cell, ensuring the cell maintains its internal environment.
* Shape maintenance: While not as rigid as a cell wall, the cell membrane contributes to the overall shape of the cell.
Key difference: The cell wall is a rigid structure made primarily of cellulose, while the cell membrane is a flexible structure composed primarily of phospholipids and proteins.
Even though they have different compositions and structures, both the cell wall and the cell membrane perform essential functions for their respective cell types.
