Tonoplast
The tonoplast is a selectively permeable biomembrane that separates the central vacuole of a plant cell from the cytoplasm .
It is permeable to certain substances that are stored in the vacuole. Due to its selective permeability, it also plays a role in osmotic processes in the plant cell. This is the case, for example, with water absorption by the cell or plasmolysis . The turgor pressure can also be explained on the basis of this property.