Block 4

Cytoskeleton

A network of protein fibers that gives a cell shape, support, and movement.

Motor proteins

Proteins that use energy to move materials around the cell.

Microtubules

Hollow protein tubes that help support the cell and move materials inside it.

Actin

A protein that forms thin filaments involved in cell shape and movement.

Intermediate filaments

Strong protein fibers that help cells maintain their shape and resist stretching.

Tubulin

The protein that makes up microtubules.

Dynamic instability

The ability of microtubules to quickly grow and shrink.

Rho GTPases

 Proteins that control cell shape, movement, and organization of the cytoskeleton.

Cdc42

 A Rho GTPase that helps cells develop direction and form extensions.

Rac

A Rho GTPase that helps cells spread out and form broad extensions.

Rho

A Rho GTPase that helps cells contract and form stress fibers.

Kinesins

Motor proteins that usually move materials toward the positive end of microtubules.

Dyneins

 Motor proteins that usually move materials toward the negative end of microtubules.