cytoskeleton

how many types?

3

type names

microtubules, microfilaments, intermediate filaments

microtubules

Composed of tubulin monomers

• hollow

• organelle movement

• chromosome movement

• cell motility (cilia and flagella)

microfilaments

Composed of actin protein monomers

• Muscle contractions (slide along myosin filaments)

• cell motility (pseudopodia during phagocytosis)

• cell division (cleavage furrow)

• cytoplasmic streaming (move fluid throughout the cell to circulate its content)

intermediate filaments

Composed of mainly keratin proteins

• Fix organelle location

• nucleus shape and rigidity (nuclear lamina)

flagella

• spins in wavelike motions

• one or few/cell

• long

  • ex.: sperm cells

cilia

• move like an oar (come and go, frog swimming)

• hair-like

• short

• many on cell surface

  • ex.: movement of fluids (mucus)