1 / 9

Vacuoles

By Jeffrey Ho, Jesse Bogdan , and Maggie Klureza. Vacuoles. Basics of Vacuoles. Vacuoles are: relatively large, membrane-bound organelles not a distinct shape but rather appear as expandable sacs that are often filled with water, organic and inorganic material

deanne
Download Presentation

Vacuoles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. By Jeffrey Ho, Jesse Bogdan, and Maggie Klureza Vacuoles

  2. Basics of Vacuoles • Vacuoles are: • relatively large, membrane-bound organelles • not a distinct shape but rather appear as expandable sacs that are often filled with water, organic and inorganic material • primarily found in plant and fungi cells, occasionally in protist and bacterial cells, but never in animal cells • generally used for structural support, waste removal and storage, but can have distinctive functions for certain cells • both structure and function can vary between different vacuoles, even between two in the same cell

  3. General Structure – Plants and Fungi • Plant and fungi cells have one large, central vacuole, which can take up as much as 80% of the space in the cell. This vacuole is made up of: • Tonoplast, the membrane which encloses the vacuole • Cell sap, the liquid that fills the vacuole instead of protoplasm • Because it is enclosed by a membrane, the vacuole is part of the endomembrane system. Essentially, this means that it is part of a group of organelles made from membranes, connected by the cytoplasmic network.

  4. General Structure – Plants and Fungi

  5. Vacuoles in Animals? • Vacuoles are only found in plant cells, fungi cells and some protist and bacteria cells, NOT in animal cells. • Animal cells DO have similar organelles, known as vesicles. • Vesicles are generally much smaller than vacuoles but much more abundant. Whereas plant and fungi cells often only have one, animal cells can have many. • Vesicles can have slightly different functions than vacuoles and are also used for transporting material from one part of the cell to another. • In lower-level sources, the two terms, vesicle and vacuole, are sometimes combined under the term “vacuole”. This is technically incorrect but more a matter of terminology than concept.

  6. General Functions in Cells • Though specific function varies between different vacuoles, the majority of vacuoles share the following functions: • Containment – storing, decomposing or removing unwanted substances from the cell’s interior • Protection – storing and isolating dangerous substances, toxic to the cell’s health • Defense – storing chemicals to be used against invading bacteria • Autophagy – breaking down and decomposing old cell parts at a rate that balances out the production of cell organelles • Homeostasis – maintaining an acidic internal pH, turgor pressure and fluid balance

  7. Specific Functions – Plants and Fungi • In addition to the general functions, in plant and fungi cells, where vacuoles play major roles, vacuoles may also have the following functions: • Growth and Development – storing salts, minerals, nutrients, and proteins that assist in plant growth • Attraction – storing pigment that provides the plant and its flowers their color, allowing them to attract insects for pollination • Defense – releasing poisonous or irritating molecules and chemicals that discourage predators from consuming the plant • Structure – exerting pressure against the plant’s cell walls, enabling the cell to maintain its form

  8. Glossary • Cell Sap – the liquid enclosed in the vacuole (as opposed to cytoplasm); is composed primarily of water, but exact composition can vary from cell to cell. • Tonoplast – literally meaning stretching, it is the cytoplasmic membranes of vacuoles • Turgor Pressure - the pressure the vacuole exerts on a plant or fungi cell’s wall, which is determined by the volume of water in the vacuole • Vesicles – similar to vacuoles but are smaller and have some different functions; they are found in animal cells

  9. Bibliography Pictures • http://www.tutorvista.com/biology/function-of-vacuole • www.library.thinkquest.org • www.micro.magnet.fsu.edu/cells/plants/vacuole.html Information • www.newton.dep.anl.gov/askasci/zoo00/zoo00296.htm • www.dictionary.reference.com/browse/vacuoles • www.iscid.org/encyclopedia/Vacuole • http://www.buzzle.com/articles/vacuole-function.html

More Related