ühekordse membraaniga (tonoplast) ümbritsetud taimede, seente, loomade ja teatud protistide rakkudes esinev organell, A single membrane-bound organelle which is present in all plant and fungal cells and some protist, animal and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed. It is also important for maintaining the turgor pressure.