Cytoskeleton Structure Determines Function Kyndal Goodwin – B3

The cytoskeleton is made up of: -Actin filaments (also called microfilaments) - Intermediate filaments -Microtubules Function: - maintains cell shape - protects the cell - enables cellular motion - plays an important role in intracellular transport - is very important in cell division - aids movement of materials in and out of cells

The cytoskeleton is a three-dimensional structure that fills the cytoplasm in eukaryotic and prokaryotic cells. Its structure acts as a muscle and skeleton, for movement and stability. The long fibers of the cytoskeleton are polymers of subunits.

Microfilaments: thread-like protein fibers composed of a protein called Actin, which is the most abundant cellular protein. Microfilaments' are responsible for muscle contraction and carry out cellular movements including gliding, contraction, and cytokinesis.

Microtubules: Cylindrical tubes composed of subunits of the protein tubulin. Microtubules determine cell shape, and provide a set of "tracks" for cell organelles and vesicles to move on. They form the spindle fibers for separating chromosomes during mitosis and are used for locomotion inside flagella and cilia.

Intermediate filaments: Fibrous proteins that are an important structural and functional element of the cytoskeleton. They function as tension-bearing elements to help maintain cell shape and rigidity. Intermediate filaments are also involved in formation of the nuclear lamina. A variety of proteins such as keratin, vimentin and desmin, bind to intermediate filaments to improve stability or to provide attachment sites for other proteins, such as the Actin filaments and microtubules.