Vacuoles

Vacuole

A vacuole is a fluid filled sac bounded by a single membrane. Animal cells contain relatively small vacuoles, such as phagocytic vacuoles, food vacuole, autophagic vacuoles and contractile vacuoles. Typically plant cells have a large central vacuole. It is formed by coalescence of smaller vacuoles during the plant’s growth and development. These are filled with watery fluid called cell sap that gives added support to the cell. Plant vacuoles contain not only water sugar and salts but also pigments and toxic molecules. The pigments are responsible for many of the red, blue or purple colors of the flowers and leaves. The toxic substances help to protect a plant from herbivorous animals. Vacuoles contribute to the rigidity of the leaves and younger roots of the plants.