Eukaryotes - Vacuoles

Description:

Vacuoles are membrane bound space found in the cytoplasm. They contain water, sap, excretory product and other materials which are not useful for the cell.

Vacuole is bound by a single membrane called tonoplast.

In plant cells vacuoles occupy about 90% of the cell volume. In plant cells tonoplast helps in the transport of a number of ions and other materials against concentration gradients into the vacuole.

In amoeba vacuoles are important for excretion.

In some cells like in protists, food vacuoles are formed by engulfing the food particles.