Cytoskeleton
The eukaryotic cell is further stabilized by a cytoskeleton made up of tubulin containing microtubules (25 nm diameter), microfilaments (4–7 nm diameter), and intermediate fibers (8–10 nm diameter). The cytoskeleton is a dynamic structure, providing support for the cell but also the machinery for ameboid movement, cytoplasmic streaming, and nuclear and cell division.