digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

Cell biology
The animal cell
Animal Cell.svg
Components of a typical animal cell:
  1. Nucleolus
  2. Nucleus
  3. Ribosome (little dots)
  4. Vesicle
  5. Rough endoplasmic reticulum
  6. Golgi apparatus (or "Golgi body")
  7. Cytoskeleton
  8. Smooth endoplasmic reticulum
  9. Mitochondrion
  10. Vacuole
  11. Cytosol (fluid that contains organelles)
  12. Lysosome
  13. Centrosome
  14. Cell membrane

The cytoplasm comprises cytosol – the gel-like substance enclosed within the cell membrane – and the organelles – the cell's internal sub-structures. All of the contents of the cells of prokaryote organisms (such as bacteria, which lack a cell nucleus) are contained within the cytoplasm. Within the cells of eukaryote organisms the contents of the cell nucleus are separated from the cytoplasm, and are then called the nucleoplasm. The cytoplasm is about 80% water and usually colorless.[1]

It is within the cytoplasm that most cellular activities occur, such as many metabolic pathways including glycolysis, and processes such as cell division. The inner, granular mass is called the endoplasm and the outer, clear and glassy layer is called the cell cortex or the ectoplasm.

Movement of calcium ions in and out of the cytoplasm is thought to be a signaling activity for metabolic processes.[2]

In plants, movements of the cytoplasm around vacuoles are known as cytoplasmic streaming.

Constituents[edit]

The cytoplasm has three major elements; the cytosol, organelles and inclusions.

Cytosol[edit]

Main article: Cytosol

The cytosol is the portion of the cytoplasm not contained within membrane-bound organelles. Cytosol makes up about 70% of the cell volume and is composed of water, salts and organic molecules.[3]

The cytosol is a complex mixture of cytoskeleton filaments, dissolved molecules, and water that fills much of the volume of a cell. The cytosol also contains the protein filaments that make up the cytoskeleton, as well as soluble proteins and small structures such as ribosomes, proteasomes, and the mysterious vault complexes.[4] The inner, granular and more fluid portion of the cytoplasm is referred to as endoplasm.

Proteins in different cellular compartments and structures tagged with green fluorescent protein

Due to this network of fibres 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.

Organelles[edit]

Main article: Organelles

Organelles (literally "little organs"), are usually membrane-bound, and are structures inside the cell that have specific functions. Some major organelles that are suspended in the cytosol are the mitochondria, the endoplasmic reticulum, the Golgi apparatus, vacuoles, lysosomes, and in plant cells chloroplasts.

Cytoplasmic inclusions[edit]

Main article: Cytoplasmic inclusion

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,[5][6] to granules of energy-storage materials such as starch,[7] glycogen,[8] or polyhydroxybutyrate.[9] 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.[10] 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.

Controversy and research[edit]

The cytoplasm, mitochondria and most organelles are contributions to the cell from the maternal gamete. There is considerably less research and understanding on cytoplasmic inheritance/maternal inheritance and mitochondrial DNA compared to the cell nucleus and genomic DNA. Historically, there has been neglect of researching whatever has been labeled female. The cytoplasm is one organelle that has been labeled feminine.[11] The cytoplasm/nucleus being labeled as feminine/masculine follows the example of egg/sperm being gendered; both cytoplasm and egg are considered nonresistant to the efforts and pursuits of the active nucleus and sperm. The "passivity of the egg becomes the passivity of the cytoplasm."[12] Contrary to the older information that disregards any notion of the cytoplasm being active, new research has shown it to be in control of movement and flow of nutrients in and out of the cell by "viscoplastic behavior and... a measure of the reciprocal rate of bond breakage within the cytoplasmic network."[13]

See also[edit]

References[edit]

  1. ^ Franklin Institute (November 23, 2013). "Cytoplasm". fi.edu. 
  2. ^ C. Michael Hogan. 2010. Calcium. eds. A.Jorgensen, C. Cleveland. Encyclopedia of Earth. National Council for Science and the Environment.
  3. ^ Cytoplasm Composition. menloschool.org
  4. ^ van Zon A, Mossink MH, Scheper RJ, Sonneveld P, Wiemer EA (September 2003). "The vault complex". Cell. Mol. Life Sci. 60 (9): 1828–37. doi:10.1007/s00018-003-3030-y. PMID 14523546. 
  5. ^ Prychid, Christina J.; Rudall, Paula J. (1999). "Calcium Oxalate Crystals in Monocotyledons: A Review of their Structure and Systematics". Annals of Botany 84 (6): 725. doi:10.1006/anbo.1999.0975. 
  6. ^ Prychid, C. J.; Rudall, P. J.; Gregory, M. (2004). "Systematics and Biology of Silica Bodies in Monocotyledons". The Botanical Review 69 (4): 377–440. doi:10.1663/0006-8101(2004)069[0377:SABOSB]2.0.CO;2. JSTOR 4354467. 
  7. ^ Ball SG, Morell MK (2003). "From bacterial glycogen to starch: understanding the biogenesis of the plant starch granule". Annu Rev Plant Biol 54: 207–33. doi:10.1146/annurev.arplant.54.031902.134927. PMID 14502990. 
  8. ^ Shearer J, Graham TE (April 2002). "New perspectives on the storage and organization of muscle glycogen". Can J Appl Physiol 27 (2): 179–203. doi:10.1139/h02-012. PMID 12179957. 
  9. ^ Anderson AJ, Dawes EA (1 December 1990). "Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates". Microbiol. Rev. 54 (4): 450–72. PMC 372789. PMID 2087222. 
  10. ^ Murphy DJ (September 2001). "The biogenesis and functions of lipid bodies in animals, growth and microorganisms". Prog. Lipid Res. 40 (5): 325–438. doi:10.1016/S0163-7827(01)00013-3. PMID 11470496. 
  11. ^ Schiebinger, Londa (1999). Has feminism changed science?. Cambridge: Harvard University Press. p. 147. ISBN 0674005449. 
  12. ^ Hess, David J. (1995). Science and Technology in a Multicultural World. New York: Columbia University Press. p. 30. ISBN 023110197X. 
  13. ^ Feneberg, Wolfgang; Sackmann, Erich, Westphal, Monika (21). "Dictyostelium cells' cytoplasm as an active viscoplastic body". European Biophysics Journal 30 (4): 284–94. doi:10.1007/s002490100135. PMID 11548131. 

External links[edit]


Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Cytoplasm — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.

108 news items

 
Nature.com
Wed, 30 Jul 2014 10:07:28 -0700

Two studies provide evidence that the protein complex PTEX is needed for export of malaria-parasite proteins into the cytoplasm of infected cells, and that such export is essential for parasite survival. See Letters p.587 & p.592 ...
 
Science Careers Blog
Thu, 31 Jul 2014 11:07:26 -0700

We used electron microscope imaging and 3D reconstruction to follow sieve element morphogenesis in Arabidopsis. We show that sieve element differentiation involves enucleation in which the nuclear contents are released and degraded in the cytoplasm at ...
 
Science Careers Blog (subscription)
Thu, 31 Jul 2014 10:48:45 -0700

It stimulates DNA repair and organizes a molecular complex necessary for sorting proteins in the cytoplasm. Pederson and colleagues recently identified a hint of yet another function. “We've discovered a small number of microRNAs in the nucleolus,” he ...
 
Australian Life Scientist
Thu, 31 Jul 2014 18:07:30 -0700

Dynamin is involved in the pinching off of invaginating vesicles from the cell membrane, allowing them enter the cell cytoplasm. “The set of three compounds we recently published on are to help people figure out how to make the compounds, fine-tune ...
 
HealthCanal.com
Thu, 31 Jul 2014 14:22:30 -0700

In the first study, they showed that injuring the endothelium by exposing it to oxidized LDL releases arginase 2 from its primary location in mitochondria and causes it to flood into the cytoplasm, impeding nitric oxide availability and causing a sharp ...

Phys.Org

Phys.Org
Wed, 30 Jul 2014 06:07:30 -0700

The cell cytoplasm (blue) interacts with the cell membrane (red) through actomyosin activity (silver rods), as simulated using the particle dynamics model. Credit: A*STAR Institute of High Performance Computing. A computer-based model of cell particle ...
 
Scicasts
Thu, 31 Jul 2014 05:00:00 -0700

These polysaccharides are assembled from substrates of simple nucleotide sugars which are transported into the Golgi apparatus from the cytosol, the gel-like liquid that fills a plant cell's cytoplasm. Despite their importance, few plant nucleotide ...

Phys.Org

Phys.Org
Wed, 30 Jul 2014 05:20:03 -0700

For many years, scientists have known how the basic building blocks of the cell wall are assembled inside the cell cytoplasm, and how the blocks are stitched together on the cell surface to construct the wall. What has remained puzzling is how the ...
Loading

Oops, we seem to be having trouble contacting Twitter

Talk About Cytoplasm

You can talk about Cytoplasm with people all over the world in our discussions.

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!