What is Vacuole?
[[File:biological cell.svg|thumb|200px|Schematic of typical animal cell, showing subcellular components. [[Organelle]]s: <br /> (1) [[nucleolus]] <br /> (2) [[cell nucleus|nucleus]] <br /> (3) [[ribosome]] <br /> (4) [[vesicle]] <br /> (5) rough [[endoplasmic reticulum]] (ER) <br /> (6) [[Golgi apparatus]] <br /> (7) [[Cytoskeleton]] <br /> (8) smooth ER <br /> (9) [[mitochondrion|mitochondria]] <br /> (10) '''vacuole''' <br /> (11) [[cytoplasm]] <br /> (12) [[lysosome]] <br /> (13) [[centriole]]s]] A '''vacuole''' is a [[Plasma membrane|membrane]]-bound [[organelle]].<ref>{{cite book | last = Venes | first = Donald | name-list-style = vanc | date = 2001 | title = Taber's Cyclopedic Medical Dictionary | edition = 20th | publisher = F.A. Davis | location = Philadelphia | page = 2287 | isbn = 0-9762548-3-2 }}</ref> They are a kind of [[vesicle]]. Vacuoles are closed sacs, made of [[membrane]]s with inorganic or organic molecules inside, such as [[enzymes]]. They have no set shape or size, and the cell can change them as needed. They are in most eukaryotic [[cell]]s and do many things. They can store waste. Vacuoles and their contents are distinct from the [[cytoplasm]], and are classified as [[Ergastic substance|ergastic]] according to some people.<ref>Esau K. 1965. ''Plant Anatomy'', 2nd ed. John Wiley.</ref> The solution that fills the vacuole is called cell sap. What a vacuole does and how important it is depends on what kind of cell they are in. They are much more important in plant and fungus cells than in animal cells. Some common jobs of a vacuole are to: * Hold waste products, and keep things separate from the rest of the cell * Hold water in plant cells * Keep the internal hydrostatic [[pressure]] or [[turgor]] steady in a cell. In land plants, this holds the stem upright. * Keep an [[acid]]ic [[pH]] on the inside of a cell * Hold small molecules * In seeds, proteins that seeds use to sprout are put in 'protein bodies'. Protein bodies are just vacuoles that are a little bit different from