introduction cell walls
plastids cytoskeleton
vacuoles microbodies

Plant cells: cytoskeleton

Cytoskelton functions:

1. mechanical support system made up of of a network of filaments

2. maintains organelle position

3. directs cell expansion

4. control movement of CH's during cell division

5. channels for transporting large molecules within the cell

Filament types:

Largest. a. Microtubules: hollow tubes ( 18-25nm/dia) dimer composition alpha and beta tubulin

Smallest b. Actin filaments - 2 intertwined strands of globular actin ( 4-7 nm/dia)

Intermediate c. Intermediate filaments - fibrous proteins approximately 10 nm

These filaments are dynamic- they can be broken down and reformed as need be... i.e. colchicine