cell vacuole
a membrane-bound sac that is found in many cells, normally acting as a storage organ of various types. A large central vacuole is a particular feature of many plant cells, where it can occupy 80-90% of the total cell volume.
Plant Cell Vacuoles
Vacuoles are membrane-bound sacs within the cytoplasm of a cell that function in several different ways.
The plant cell vacuole also regulates turgor pressure in the cell. Water collects in cell vacuoles, pressing outward against the cell wall and producing rigidity in the plant. Without sufficient water, turgor pressure drops and the plant wilts.
contractile vacuole A clear fluid-filled cell vacuole in protozoa and a few lower metazoa; takes up water and releases it to the outside in a cyclical manner, for osmoregulation and some excretion.
 See also: Endoplasmic reticulum, Cell, Membrane, Animal, Trans
|
