Microfilaments

Three kinds of microfilaments?

Microtubules
Microfilaments
Intermediate filaments

Microtubules?

Maintenance of cell shape
Motility (Flagella or cilia)
Movement of organelles through cell (Often involves motor molecule)
Often originate from centrosome

Largest microfilament?

Microtubules

Smallest mircofilament?

Microfilaments

Cilia

small appendages and they move like a swimmer’s arm-active
stroke and return stroke

Flagella

eukaryotic flagella undulate

Motor molecules

interact with tubulin or actin
Are fixed at one end and allowed to move freely at the other end
Movement is directional

Microfilaments?

Made of two intertwined strands of actin
Helps maintain cell shape
Actin rearrangements allow engulfment events
Psuedopodia formation in ameoba
Promote cytoplasmic streaming in plants
Essential for muscle contraction
Frequently being assembled and disassembled within cell

Intermediate filaments?

Resemble cable in structure
Are made of protein subunits like keratin and laminin
Help maintain cell shape and keep organelles in place
Are durable and not assembled and disassembled as other cytoskeleton
components