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 exoskeleton, 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. 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."[11]

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. ^ 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.  Check date values in: |date= (help)

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.
8185 videos foundNext > 

Cytoplasm

This video describes the cell's cytoplasm.

Cytoskeleton - Cytoplasm

Science Help at Brightstorm! http://brightstorm.com/science The structure of cytoskeleton.

The Cytoplasm.flv

Cytoplasm

This is a synthesized speech reading of the Wikipedia article "Cytoplasm" and is intended primarily for blind and visually impaired individuals who can not v...

Chapter 3 Module 1 Cytoplasm and Organelles

The Nucleus and Cytoplasm Song (Call Me Maybe & Gangnam Style Song Parody) by Annalee&Aubrey

A biology project about the cell nucleus and cytoplasm. Me and my lovely friend made our own lyrics to the song for each topic, and this is the result! At th...

The Cytoplasm Blues

This was the first Melodic-Mnemonic song I wrote during my first year as a science teacher at Crenshaw High School in South Central Los Angeles back in 1989....

3a Nucleus, cytoplasm and plasma membrane

CYTOPLASM MOVIE

MOVIE.

Cytoplasm ... السيتوبلازم

تركيب السيتوبلازم اهمية السيتوبلازم للخليه السيتوسول - العضيات - الهيكل الخلوي.

8185 videos foundNext > 

2274 news items

 
Nature.com
Wed, 26 Nov 2014 10:12:59 -0800

For tumour-infiltrating immune cells, the percentage of PD-L1-positive tumour-infiltrating immune cells occupying the tumour was recorded; tumour-infiltrating immune cells with clearly discernible cytoplasm, such as macrophages and dendritic cells ...

Science 2.0

Harvard School of Engineering and Applied Sciences
Thu, 14 Aug 2014 09:07:30 -0700

Cambridge, Mass. – August 14, 2014 – Conventional wisdom holds that the cytoplasm of mammalian cells is a viscous fluid, with organelles and proteins suspended within it, jiggling against one another and drifting at random. However, a new biophysical ...
 
7thSpace Interactive (press release)
Fri, 28 Nov 2014 05:41:15 -0800

A major challenge to the clinical utility of let-7 for hepatocellular carcinoma (HCC) therapy is the lack of an effective carrier to target tumours. We confirmed the high transfection efficiency of cholesterol-conjugated let-7a miRNA mimics (Chol-let ...
 
Nature.com
Mon, 24 Nov 2014 08:09:53 -0800

These findings suggested that the molecular structure of upstream CaMK kinase, CaMKK-α and CaMKK-β, contained a versatile Ca2+-sensing mechanism that was efficiently turned on during biologically relevant rises in calcium in the neuronal cytoplasm22.

Seeking Alpha

Seeking Alpha
Tue, 25 Nov 2014 07:30:18 -0800

The mRNA is transported out of the nucleus and into the cytoplasm. It binds to a protein complex called a ribosome, which reads the sequence and translates the code of the mRNA into a protein (called "translation"). One amino acid is added for every ...
 
Nature.com
Mon, 24 Nov 2014 02:55:42 -0800

A moderate decrease in EGFR mRNA level was noticed in HCC1937B cells (Figure 2b). Subcellular fractionation of HCC1937 and HCC1937B cells showed accumulation of p-EGFR (Y-1068) in the cytoplasm of BRCA1 null cells (Figure 2c, lanes 1 and 2).

Vanderbilt University News

Vanderbilt University News
Tue, 18 Nov 2014 08:36:18 -0800

As provost, she will continue to run her lab and pursue work aimed at furthering knowledge of the exchange mechanism for proteins and genetic material between the nucleus and cytoplasm. As Vanderbilt's senior associate dean of biomedical sciences, she ...
 
STV Dundee
Wed, 26 Nov 2014 01:56:15 -0800

The fact it bears striking similarity to a famous painting was totally coincidental. "As happens at times with science, something totally unexpected appears that can be very beautiful.” Microtubules are a hollow cylindrical structure in the cytoplasm ...
Loading

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

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

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight