Cell wall
Cell wall provides most significant difference between plant cells and animal cells:
Only in animal cells
Layer that surrounds some types of cells and is located outside the cell membrane
Composed of Cellulose (specialized sugars)
Cellulose fibrils are deposited in alternating layers for strength
Pores in cell wall make it permeable, so let water, nutrients, waste, ions pass through -> called plasmodesmata
Rigid structure <- lost opportunity to develop nervous system, immune system and the mobility
Function:
Protection from physical injury
Maintains shape
In young cells the cell wall is not so rigid and thick so cell can grow:
‘Primary cell wall'
After growth cell walls thickens or it may deposit new layers of different material:
‘Secondary cell wall' All cell walls form a tightly bound plant structure Bacteria, Fungi, Ptotoza have cell wall but not the same
These may be made from proteins or chitin
Also for protecting and to maintain structure