Cyclosis, or cytoplasmic streaming, occurs due to the activity of microfilaments, which are part of the cell's cytoskeleton. These microfilaments facilitate the movement of cytoplasm within the cell. Motor proteins attached to microfilaments transport organelles and molecules within the cytoplasm. Myosin molecules attached to cellular organelles travel along the actin filaments, pulling the organelles and pushing other cytoplasmic contents in the same direction.