cytoskeleton

The cytoskeleton (also CSK) is a cellular scaffolding or skeleton contained within a cells cytoplasm and is made out of protein.

The cytoskeleton is present in all cells; it was once thought to be unique to eukaryotes, but recent research has identified the prokaryotic cytoskeleton. It has structures such as flagella, cilia and lamellipodia and plays important roles in both intracellular transport (the movement of vesicles and organelles, for example) and cellular division.