THE CELLULOSE CELL WALL

Cross-section of a cell wall with an Electron microscope. Rumex conglomeratus.

>Cell walls are found only in plant cells and consist of many cellulose fibres

>Cell walls have four layers; the outer-most layer is called the middle lamella. The middle lamella contains the micro fibrils and is capable of expanding during growth. Three other layers the primary; secondary and territary follow the middle lamella.

>Micro fibrils are 2000 parallel cellulose molecules packed together. Micro fibrils are also packed together and form fibrils.

>The cell wall has great strength because many strong fibres hold it together.

>The functions of cell walls are to provide rigidity and strength AND to force the cell to assume a certain shape.