'''Cytoplasm''' is awater-likesubstancethat fills [[Cell (biology)|cell]]s.Thecytoplasmconsistsof [[cytosol]] and the cellular [[organelles]],except the [[cell nucleus]]. The cytosol is made up of water, salts,organic molecules and many [[enzymes]] that catalyzereactions.Thecytoplasmplaysanimportantrolein a cell, serving as a "molecular chowder" in which the organelles are suspended and held together by a fatty membrane. It is foundwithintheplasmamembraneofacellandsurroundsthenucleus and envelopestheorganelles.
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The '''cytoplasm''' is thepartsofa [[Cell (biology)|cell]] thatareenclosedwithin the [[plasma membrane]].In [[eukaryote|eukaryotic]] cells the cytoplasm contains [[organelle]]s, suchas [[mitochondrion|mitochondria]], that arefilledwithliquidkeptseparatefromtherestof the cytoplasm by [[cell membrane]]s. The cytoplasm is thesitewheremostcellularactivitiesoccur,suchasmany[[metabolicpathway]]s, and processessuch as celldivision.
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==Function==
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The part of the cytoplasm that is not held within organelles is called the [[cytosol]]. The cytosol is a complex mixture of [[cytoskeleton]] filaments, dissolved molecules, and water that fills much of the volume of a cell. The cytosol is a [[gel]], with a network of fibers dispersed through water. Due to this network of pores and high concentrations of dissolved [[macromolecule]]s, such as [[protein]]s, an effect called [[macromolecular crowding]] occurs and the cytosol does not act as an [[ideal solution]]. This crowding effect alters how the components of the cytosol interact with each other.
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The cytoplasm holds all of the cellular organelles outside of the nucleus and also maintains the shape and consistency of the cell. It is also a storage place for chemical substances indispensable to life, which are involved in vital [metabolism|metabolic] reactions, such as [anaerobic glycolysis] and [protein] [synthesis]it is made up of 80% water.
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Inbacteria,sequential chemical reactions take place in the cytoplasm and cell.
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==Constituents==
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==Componentsof the cytoplasm==
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Thecytoplasm has three major elements; the [[cytosol]], [[organelles]] and [[inclusions]].
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The cytoplasm is composed of [[ion]]s and soluble [[macromolecule]]s like [[enzyme]]s, [[carbohydrate]]s, different [[salt]]s and [[protein]]s, as well as a great proportion of [[RNA]]. The cytoplasm's watery component is also known as [[hyaloplasm]].
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Itcanbe more or less [[water]]-like or liquid depending on the milieu's conditions and the activity phases of the cell. In the first case, it is named [[cytogel]] and is a viscous solid mass. In the second case, called [[cytosol]], it acts like a liquid. In general, margin regions of the cell are water-like, and the cell's interior is RNA.
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===Cytosol===
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The [[organelle]]s(such asthe [[mitochondria]],the [[chloroplast]], [[lysosome]]s, [[peroxysome]]s, [[ribosome]]s, [[vacuole]]s, [[cytoskeleton]]s, and complex [[cell membrane]] structures likethe [[endoplasmicreticulum]]s) in the cytoplasm are insoluble.
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[[Image:Localisations02eng.jpg|thumb|right|250px|Proteinsindifferent [[cellularcompartment]]s and structures taggedwith [[greenfluorescent protein]].]]
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The cytosol is the portion of a cell that is not enclosed within membrane-bound organelles. The cytosol is a translucent fluid in which the other cytoplasmic elements are suspended. Cytosol makes up about 70 % of the cell volume and is composed of water, salts and organic molecules.<ref>[http://sun.menloschool.org/~birchler/cells/animals/cytoplasm/ Cytoplasm Composition]</ref> The cytoplasm also contains the [[protein filament]]s that make up the [[cytoskeleton]], as well as soluble [[proteins]] and large structures such as [[ribosome]]s, [[proteasome]]s, and the mysterious [[Vault (organelle)|vault complexes]].<ref>{{cite journal |author=van Zon A, Mossink MH, Scheper RJ, Sonneveld P, Wiemer EA |title=The vault complex |journal=Cell. Mol. Life Sci. |volume=60 |issue=9 |pages=1828–37 |year=2003 |month=September |pmid=14523546 |doi=10.1007/s00018-003-3030-y}}</ref> The inner, granular and more fluid portion of the cytoplasm is referred to as endoplasm.
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=== Organelles ===
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[[Organelles]] are membrane-bound compartments within the cell that have specific functions. Some major organelles that are suspended in the cytosol are the [[mitochondria]], the [[endoplasmic reticulum]], the [[Golgi apparatus]], [[lysosomes]], and in plant cells [[chloroplast]]s.
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=== Cytoplasmic inclusions ===
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The [[inclusions]] are small particles of insoluble substances suspended in the cytosol. A huge range of inclusions exist in different cell types, and range from crystals of [[calcium oxalate]] or [[silicon dioxide]] in plants,<ref name=Prychid1999>{{citation | author = Prychid, Christina J.; Rudall, Paula J. | year = 1999 | title = Calcium Oxalate Crystals in Monocotyledons: A Review of their Structure and Systematics | journal = Annals of Botany | volume = 84 | issue = 6 | pages = 725 | doi = 10.1006/anbo.1999.0975 | url = http://aob.oxfordjournals.org/cgi/content/abstract/84/6/725}}</ref><ref name=Prychid2003>{{citation | author = Prychid, C. J.; Rudall, P. J.; Gregory, M. | year = 2003 | title = Systematics and Biology of Silica Bodies in Monocotyledons | journal = The Botanical Review | volume = 69 | issue = 4 | pages = 377–440 | doi = 10.1663/0006-8101(2004)069[0377:SABOSB]2.0.CO;2 | url = http://www.bioone.org/perlserv/?request=get-abstract}}</ref> to granules of energy-storage materials such as [[starch]]s,<ref>{{cite journal |author=Ball SG, Morell MK |title=From bacterial glycogen to starch: understanding the biogenesis of the plant starch granule |journal=Annu Rev Plant Biol |volume=54 |issue= |pages=207–33 |year=2003 |pmid=14502990 |doi=10.1146/annurev.arplant.54.031902.134927}}</ref> [[glycogen]],<ref>{{cite journal |author=Shearer J, Graham TE |title=New perspectives on the storage and organization of muscle glycogen |journal=Can J Appl Physiol |volume=27 |issue=2 |pages=179–203 |year=2002 |month=April |pmid=12179957}}</ref> or [[polyhydroxybutyrate]].<ref>{{cite journal |author=Anderson AJ, Dawes EA |title=Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates |journal=Microbiol. Rev. |volume=54 |issue=4 |pages=450–72 |year=1990 |month=December |pmid=2087222 |pmc=372789 |url=http://mmbr.asm.org/cgi/pmidlookup?view=long&pmid=2087222}}</ref> A particularly widespread example are [[lipid droplet]]s, which are spherical droplets composed of lipids and proteins that are used in both prokaryotes and eukaryotes as a way of storing lipids such as [[fatty acid]]s and [[sterol]]s.<ref>{{cite journal |author=Murphy DJ |title=The biogenesis and functions of lipid bodies in animals, plants and microorganisms |journal=Prog. Lipid Res. |volume=40 |issue=5 |pages=325–438 |year=2001 |month=September |pmid=11470496}}</ref> Lipid droplets make up much of the volume of [[adipocyte]]s, which are specialized lipid-storage cells, but they are also found in a range of other cell types.
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== References ==
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{{reflist|2}}
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== Further reading ==
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* Alberts, Bruce et al. (2003). ''Essential Cell Biology,'' 2nd ed., Garland Science, 2003, ISBN 081533480X.
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* Human Anatomy & Physiology, seventh edition By; Elain N Marieb and Latja Hoehn.
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== External links ==
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* [http://wiwi.essortment.com/cytoplasm_rkkg.htm What is cytoplasm?] - by Genevieve Theirs -2002
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* Luby-Phelps K. [http://www.rpgroup.caltech.edu/courses/aph161/Handouts/Luby-Phelps2000.pdf Cytoarchitecture and physical properties of cytoplasm: volume, viscosity, diffusion, intracellular surface area.] ''Int Rev Cytol.'' 2000;192:189-221.
The cytoplasm is the parts of a cell that are enclosed within the plasma membrane. In eukaryotic cells the cytoplasm contains organelles, such as mitochondria, that are filled with liquid kept separate from the rest of the cytoplasm by cell membranes. The cytoplasm is the site where most cellular activities occur, such as many metabolic pathways, and processes such as cell division.
The part of the cytoplasm that is not held within organelles is called the cytosol. The cytosol is a complex mixture of cytoskeleton filaments, dissolved molecules, and water that fills much of the volume of a cell. The cytosol is a gel, with a network of fibers dispersed through water. Due to this network of pores and high concentrations of dissolved macromolecules, such as proteins, an effect called macromolecular crowding occurs and the cytosol does not act as an ideal solution. This crowding effect alters how the components of the cytosol interact with each other.
The cytosol is the portion of a cell that is not enclosed within membrane-bound organelles. The cytosol is a translucent fluid in which the other cytoplasmic elements are suspended. Cytosol makes up about 70 % of the cell volume and is composed of water, salts and organic molecules.[1] The cytoplasm also contains the protein filaments that make up the cytoskeleton, as well as soluble proteins and large structures such as ribosomes, proteasomes, and the mysterious vault complexes.[2] The inner, granular and more fluid portion of the cytoplasm is referred to as endoplasm.
The inclusions are small particles of insoluble substances suspended in the cytosol. A huge range of inclusions exist in different cell types, and range from crystals of calcium oxalate or silicon dioxide in plants,[3][4] to granules of energy-storage materials such as starchs,[5]glycogen,[6] or polyhydroxybutyrate.[7] A particularly widespread example are lipid droplets, which are spherical droplets composed of lipids and proteins that are used in both prokaryotes and eukaryotes as a way of storing lipids such as fatty acids and sterols.[8] Lipid droplets make up much of the volume of adipocytes, which are specialized lipid-storage cells, but they are also found in a range of other cell types.
↑Ball SG, Morell MK (2003). From bacterial glycogen to starch: understanding the biogenesis of the plant starch granule. Annu Rev Plant Biol54: 207–33.
↑Shearer J, Graham TE (April 2002). New perspectives on the storage and organization of muscle glycogen. Can J Appl Physiol27 (2): 179–203.
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