Vacuoles are fluid containing, membrane-bound organelles that serve a variety of purposes depending on the cell they are found in. They are predominantly found in plant and fungal cells, where their main importance is exerting turgor pressure; an osmotic pressure that prevents the cell from wilting. Vacuoles are able to do this as they contain a large amount of water, due to a high concentration of solutes, causing water to enter by osmosis. Therefore, they are swollen and press against the cell wall allowing the plant to maintain its shape.
Vacuoles can also be found in some animal, bacterial cells and protist cells, where they are used for processes such as storage and transport. For example, food particles taken up by protozoa can be surrounded by the plasma membrane to form a type of vacuole called a phagosome, later broken down to provide a source of nutrients for the cell .
- ↑ Becker, W.M. et al., 2009; p93, The World Of The Cell, 7th edition, San Francisco: Pearson Education, Inc.