provides structural support to the cell and determines its shape.
is a network of fibrillar proteins.
These fibrilar proteins are synthesized by polymerization of precursor molecules → if not needed anymore → disassemble → reassemble where and where needed → thus the cytoskeleton can be dynamic as needed.
polymer of tubulin.
have a hollow lumen at the center.
20-30 nm in diameter.
Form and move structures like:
Form a track for intracellular organelles to move from one area of the cell to the other
Thin & Thick Filaments
Thin filaments are made up of actin
Thick filaments are made up of myosin
Functions: They play role in...
Cell movement e.g. gliding, cytokinesis
Extend process from cell e.g.
Formation of axon in neuron
Formation of microvilli in epithelial cells
There is a large variety of subunit proteins that can form intermediate filaments.
Expression of different subunits in different cells results in formation of different intermediate filaments in different cells. For example:
Epithelial cells have keratins
Nerve cells have neurofilaments
Muscle cells have desmin
Radiate from the cell area subject to tensile stress → Reinforce such area against tensile stress.
In epithelial cells, they insert at the desmosomal junctions that attach neighboring cells to one another.