The cytoskeleton is a network of fibers that maintains the shape of cells. The three types of fibers are actin filaments, microtubules, and intermediate filaments. Actin filaments are long fibers composed of two protein chains. They are responsible for cellular movements, such as contraction, crawling, "pinching" during division, and formation of cellular extensions. Microtubules are hollow tubes composed of a ring of thirteen protein filaments. They are responsible for moving materials within the cell. Intermediate filaments are tough, fibrous protein molecules structured in an overlapping arrangement. They are intermediate in size when compared to actin filaments and microtubules, and provide structural stability to cells.

Read more: what-are-the-three-types-of-fibers-found-in-the-cytoskeleton-of-eukaryotic-cells