Amoeba proteus protozoan exhibiting cytoplasmic streaming. The movement of cytoplasm form pseudopodia, or false feet, which enable the amoeba to move. The cell磗 organelles such as the large circular contractile vacuole and cytoplasm are enclosed by a cell membrane. The contractile vacuole controls osmoregulation by expelling water out of the cell as it contracts seen here. This acts as a protective mechanism that prevents the cell from absorbing too much water and exploding.