FACTOID # 1: Idaho produces more milk than Iowa, Indiana and Illinois combined.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Golgi apparatus
Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. Numerous circular vesicles can be seen in proximity to the organelle
Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. Numerous circular vesicles can be seen in proximity to the organelle
Diagram of secretory process from endoplasmic reticuli (orange) to Golgi apparatus (pink). Please click for full labels.
Diagram of secretory process from endoplasmic reticuli (orange) to Golgi apparatus (pink). Please click for full labels.

The Golgi apparatus (also called the Golgi body, Golgi complex, or dictyosome) is an organelle found in typical eukaryotic cells. It was identified in 1898 by the Italian physician Camillo Golgi and was named after him. The primary function of the Golgi apparatus is to process and package macromolecules synthesised by the cell, primarily proteins and lipids. The Golgi apparatus forms a part of the endomembrane system of eukaryotic cells. Image File history File links Human_leukocyte,_showing_golgi_-_TEM.jpg‎ File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Golgi apparatus ... Image File history File links Human_leukocyte,_showing_golgi_-_TEM.jpg‎ File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Golgi apparatus ... Yours, Magnus Manske Source: [1]. See also User:Magnus Manske This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Yours, Magnus Manske Source: [1]. See also User:Magnus Manske This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Schematic of typical animal cell, showing subcellular components. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... Year 1898 (MDCCCXCVIII) was a common year starting on Saturday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Monday of the 12-day-slower Julian calendar). ... Camillo Golgi, 1906. ... A macromolecule is a large molecule with a large molecular mass bonded covalently, but generally the use of the term is restricted to polymers and molecules which structurally include polymers. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Some common lipids. ... The endomembrane system is the system of internal membranes within eukaryotic cells that divide the cell into functional and structural compartments, or organelles. ...

Contents

Structure

The Golgi is composed of membrane-bound sacs known as cisternae. Between five and eight are usually present; however, as many as sixty have been observed.[1]. This article relates to cell biology. ...


Function

Cells synthesize a large number of different macromolecules required for life. The Golgi apparatus is integral in modifying, sorting, and packaging these substances for cell secretion (exocytosis) or for use within the cell. It primarily modifies proteins delivered from the rough endoplasmic reticulum, but is also involved in the transport of lipids around the cell, and the creation of lysosomes. In this respect it can be thought of as similar to a post office; it packages and labels items and then sends them to different parts of the cell. Neuron A (transmitting) to neuron B (receiving) 1. ... The endoplasmic reticulum or ER (endoplasmic means within the cytoplasm, reticulum means little net) is an organelle found in all eukaryotic cells. ... Some common lipids. ... Organelles labeled at upper left. ...


Enzymes within the cisternae are able to modify substances by the addition of carbohydrates (glycosylation) and phosphate (phosphorylation) to them. In order to do so the Golgi transports substances such as nucleotide sugars into the organelle from the cytosol. Proteins are also labelled with a signal sequence of molecules which determine their final destination. For example, the Golgi apparatus adds a mannose-6-phosphate label to proteins destined for lysosomes. Glycosylation is the process or result of addition of saccharides to proteins and lipids. ... A phosphorylated serine residue Phosphorylation is the addition of a phosphate (PO4) group to a protein or a small molecule or the introduction of a phosphate group into an organic molecule. ... Protein targeting a. ... Mannose is a sugar, one of the hexose series of carbohydrates. ... Organelles labeled at upper left. ...


The Golgi also plays an important role in the synthesis of proteoglycans, molecules present in the extracellular matrix of animals, and it is a major site of carbohydrate synthesis.[2] Proteoglycans represent a special class of glycoprotein that are heavily glycosylated. ... Illustration depicting extracellular matrix (basement membrane and interstitial matrix) in relation to epithelium, endothelium and connective tissue In biology, the extracellular matrix (ECM) is the extracellular part of animal tissue that usually provides structural support to the cells in addition to performing various other important functions. ... For other uses, see Animal (disambiguation). ... Lactose is a disaccharide found in milk. ...


This includes the productions of glycosaminoglycans or GAGs, long unbranched polysaccharides which the Golgi then attaches to a protein synthesized in the endoplasmic reticulum to form the proteoglycan.[3]Enzymes in the Golgi will polymerize several of these GAGs via a xylose link onto the core protein. Another task of the Golgi involves the sulfation of certain molecules passing through its lumen via sulphotranferases that gain their sulphur molecule from a donor called PAPs. This process occurs on the GAGs of proteoglycans as well as on the core protein. The level of sulfation is very important to the proteoglycans' signalling abilities as well as giving the proteoglycan its overall negative charge.[2] Chondroitin sulfate Hyaluronan Glycosaminoglycans (GAGs) or mucopolysaccharides are long unbranched polysaccharides consisting of a repeating disaccharide unit. ... Polysaccharides (sometimes called glycans) are relatively complex carbohydrates. ... Proteoglycans represent a special class of glycoprotein that are heavily glycosylated. ... Polymerization is a process of reacting monomer molecules together in a chemical reaction to forinear chains or a three-dimensional network of polymer chains [1]. There are many forms of polymerization and different systems exist to categorize them. ... Xylose or wood sugar is an aldopentose — a monosaccharide containing five carbon atoms and including an aldehyde functional group. ... Sulfation refers to the process whereby a lead-acid battery (such as a car battery) loses its ability to hold a charge after it is kept in a discharged state too long due to the crystallization of lead sulfate. ...


The Golgi is also capable of phosphorylating molecules. To do so it transports ATP into the lumen.[4] The Golgi itself contains resident kinases, such as casein kinases. One molecule that is phosphorylated in the Golgi is Apolipoprotein, which forms a molecule known as VLDL that is a constitute of blood serum. It is thought that the phosphorylation of these molecules is important to help aid in their sorting of secretion into the blood serum.[5] A phosphorylated serine residue Phosphorylation is the addition of a phosphate (PO4) group to a protein or a small molecule or the introduction of a phosphate group into an organic molecule. ... Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ... Lumen can mean: Lumen (unit), the SI unit of luminous flux Lumen (anatomy), the cavity or channel within a tubular structure Thylakoid lumen, the inner membrane space of the chloroplast 141 Lumen, an asteroid discovered by the French astronomer Paul Henry in 1875 Lumen (band), an American post-rock band... In biochemistry, a kinase is a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP, to specific target molecules (substrates); the process is termed phosphorylation. ... The Casein kinase 1 family of protein kinases are serine/threonine-selective enzymes that function as regulators of signal transduction pathways in most eukaryotic cell types. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Very Low Density Lipoprotein (VLDL) is a lipoprotein subclass. ... Blood plasma is a component of blood. ... Secretion is the process of segregating, elaborating, and releasing chemicals from a cell, or a secreted chemical substance or amount of substance. ...


The Golgi also has a putative role in apoptosis, with several Bcl-2 family members localised there, as well as to the mitochondria. In addition a newly characterised anti-apoptotic protein, GAAP (Golgi anti-apoptotic protein), which almost exclusively resides in the Golgi, protects cells from apoptosis by an as-yet undefined mechanism (Gubser et al., 2007). A section of mouse liver showing an apoptotic cell indicated by an arrow Apoptosis (pronounced apo tō sis) is a process of suicide by a cell in a multicellular organism. ... B cell lymphoma (Bcl)-2 is a mammalian protein family whose members govern mitochondrial membrane permeabilisation (MMP), a key event in apoptosis. ...


Vesicular transport

Vesicles which leave the rough endoplasmic reticulum are transported to the cis face of the Golgi apparatus, where they fuse with the Golgi membrane and empty their contents into the lumen. Once inside they are modified, sorted, and shipped towards their final destination. As such, the Golgi apparatus tends to be more prominent and numerous in cells synthesising and secreting many substances: plasma B cells, the antibody-secreting cells of the immune system, have prominent Golgi complexes. artery anatomy, showing lumen The lumen (pl. ... Plasma cells are B lymphocytes that secrete immunoglobulins (antibodies). ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ...


Those proteins destined for areas of the cell other than either the endoplasmic reticulum or Golgi apparatus are moved towards the trans face, to a complex network of membranes and associated vesicles known as the trans-Golgi network (TGN).[6] This area of the Golgi is the point at which proteins are sorted and shipped to their intended destinations by their placement into one of at least three different types of vesicles, depending upon the molecular marker they carry.In other words, the golgi packages and distributes chemical messages and products such as proteins.:[6] The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ...

Type Description Example
Exocytotic vesicles (continuous) Vesicle contains proteins destined for extracellular release. After packaging the vesicles bud off and immediately move towards the plasma membrane, where they fuse and release the contents into the extracellular space in a process known as constitutive secretion. Antibody release by activated plasma B cells
Secretory vesicles (regulated) Vesicle contains proteins destined for extracellular release. After packaging the vesicles bud off and are stored in the cell until a signal is given for their release. When the appropriate signal is received they move towards the membrane and fuse to release their contents. This process is known as regulated secretion. Neurotransmitter release from neurons. In other words, the golgi packages and distributes chemical messages and products such as proteins.
Lysosomal vesicles Vesicle contains proteins destined for the lysosome, an organelle of degradation containing many acid hydrolases, or to lysosome-like storage organelles. These proteins include both digestive enzymes and membrane proteins. The vesicle first fuses with the late endosome, and the contents are then transferred to the lysosome via unknown mechanisms. Digestive proteases destined for the lysosome

Drawing of a cell membrane A component of every biological cell, the cell membrane (or plasma membrane) is a thin and structured bilayer of phospholipid and protein molecules that envelopes the cell. ... A secretory pathway is a term used to describe different methods that cells use to transport material to the outside, usually from the endoplasmic reticulum via the Golgi apparatus. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... Plasma cells are B lymphocytes that secrete immunoglobulins (antibodies). ... A secretory pathway is a term used to describe different methods that cells use to transport material to the outside, usually from the endoplasmic reticulum via the Golgi apparatus. ... Chemical structure of D-aspartic acid, a common amino acid neurotransmitter. ... Drawing by Santiago Ramón y Cajal of neurons in the pigeon cerebellum. ... Organelles labeled at upper left. ... In biochemistry, a hydrolase is an enzyme that can break a chemical bond by hydrolysis. ... In biology an endosome is a membrane-bound compartment inside cells. ... Proteases (proteinases, peptidases, or proteolytic enzymes) are enzymes that break peptide bonds between amino acids of proteins. ... Organelles labeled at upper left. ...

Transport mechanism

The transport mechanism which proteins use to progress through the Golgi apparatus is not yet clear; however a number of hypotheses currently exist. Until recently, the vesicular transport mechanism was favoured but now more evidence is coming to light to support cisternal maturation. The two proposed models may actually work in conjunction with each other, rather than being mutually exclusive. This is sometimes referred to as the combined model. [2] To meet Wikipedias quality standards, this article or section may require cleanup. ...

  • Cisternal maturation model: the cisternae of the Golgi apparatus move by being built at the cis face and destroyed at the trans face. Vesicles from the endoplasmic reticulum fuse with each other to form a cisterna at the cis face, consequently this cisterna would appear to move through the Golgi stack when a new cisterna is formed at the cis face. This model is supported by the fact that structures larger than the transport vesicles, such as collagen rods, were observed microscopically to progress through the Golgi apparatus.[2] This was initially a popular hypothesis, but lost favour in the 1980s. Recently it has made a comeback, as laboratories at the University of Chicago and the University of Tokyo have been able to use new technology to directly observe Golgi compartments maturing.[7]. Additional evidence comes from the fact that COP1 vesicles move in the retrograde direction,. transporting ER proteins back to where they belong by recognizing a signal peptide.[8]
  • Vesicular transport model: Vesicular transport views the Golgi as a very stable organelle, divided into compartments is the cis to trans direction. Membrane bound carriers transported material between the ER and Golgi and the different compartments of the Golgi.[9] Experimental evidence inlcudes the abundance of small vesicles (known technically as shuttle vesicles) in proximity to the Golgi apparatus. Directionality is achieved by packaging proteins into either forward-moving or backward-moving (retrograde) transport vesicles, or alternatively this directionality may not be necessary as the constant input of proteins from the endoplasmic reticulum on the cis face of the Golgi would ensure flow. Irrespectively, it is likely that the transport vesicles are connected to a membrane via actin filaments to ensure that they fuse with the correct compartment.[2]

Tropocollagen triple helix. ... The University of Chicago is a private university located principally in the Hyde Park neighborhood of Chicago. ... The place of the establishment of the University of Tokyo The University of Tokyo ), abbreviated as Todai ), is one of the leading research universities in Japan. ... Schematic of typical animal cell, showing subcellular components. ... This article or section should be merged with actin Microfilaments or actin filaments are made up of two twisted monomeric actin subunits. ...

Links

  • Golgi antibody

References

  1. ^ {{Cite web|url=http://micropoop rocks go [email protected]~and steelers=] . The cisternae stack has five functional regions: the cis-Golgi network, cis-Golgi, medial-Golgi, trans-Golgi, and trans-Golgi network. Vesicles from the endoplasmic reticulum (via the vesicular-tubular cluster) fuse with the cis-Golgi network and subsequently progress through the stack to the trans-Golgi network, where they are packaged and sent to the required destination. Each region contains different enzymes which selectively modify the contents depending on where they are destined to reside.<ref>{{cite book | title=Molecular Cell Biology| edition=5th edn |last=Lodish| coauthors=et al.| date=2004| publisher=W.H. Freeman and Company| id=P0-7167-4366-3}}</li> <li id="_note-alberts">^ [[#_ref-alberts_0|<sup>'''''a'''''</sup>]]&#32;[[#_ref-alberts_1|<sup>'''''b'''''</sup>]]&#32;[[#_ref-alberts_2|<sup>'''''c'''''</sup>]]&#32;[[#_ref-alberts_3|<sup>'''''d'''''</sup>]]&#32;[[#_ref-alberts_4|<sup>'''''e'''''</sup>]] {{cite book | title=Molecular Biology of the Cell| url=http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowTOC&rid=cell.TOC| last=Alberts| first=Bruce| coauthors=''et al.''| publisher=Garland Publishing}}</li> <li id="_note-0">'''[[#_ref-0|^]]''' Pyrdz, K. and K.T. Dalan, Synthesis and Sorting of Proteoglycans. Journal of Cell Science, 2000. 113: p. 193-205.</li> <li id="_note-1">'''[[#_ref-1|^]]''' Capasso, J., et al., Mechanism of phosphorylation in the lumen of the Golgi apparatus. Translocation of adenosine 5'-triphosphate into Golgi vesicles from rat liver and mammary gland. Journal of Biological Chemistry, 1989. 264(9): p. 5233-5240.</li> <li id="_note-2">'''[[#_ref-2|^]]''' Swift, L.L., Role of the Golgi Apparatus in the Phosphorylation of Apolipoprotein B. Journal of Biological Chemistry, 1996. 271(49): p. 31491-31495.</li> <li id="_note-lodish">^ [[#_ref-lodish_0|<sup>'''''a'''''</sup>]]&#32;[[#_ref-lodish_1|<sup>'''''b'''''</sup>]] {{cite book | title=Molecular Cell Biology| edition=5th edn |last=Lodish| coauthors=et al.| date=2004| publisher=W.H. Freeman and Company| id=0-7167-4366-3}}</li> <li id="_note-3">'''[[#_ref-3|^]]''' {{cite journal | author=Glick, B.S. and Malhotra, V. | title=The curious status of the Golgi apparatus | journal=Cell | year=1998 | volume=95 | pages= 883-889}}</li> <li id="_note-4">'''[[#_ref-4|^]]''' Pelham, H.R.B. and J.E. Rothman, The Debate about Transport in the Golgi - Two Sides of the Same Coin? Cell, 2000. 102: p. 713-719.</li> <li id="_note-5">'''[[#_ref-5|^]]''' Glick, B.S., Organisation of the Golgi apparatus. Current Opinion in Cell Biology, 2000. 12: p. 450-456.</li></ol></ref>
  • Golgi Complex: Structure and Function
  • Golgi Complex

  Results from FactBites:
 
Golgi apparatus (370 words)
The Golgi apparatus is present in all cells but tends to be more prominent where there are a lot of substances, such as enzymes, being secreted.
The transport vesicles from the ER fuse with the cis face of the Golgi apparatus (to the cisternae) and empty their protein content into the Golgi lumen (the internal space of the Golgi apparatus).
(11) Cisternae of the Golgi apparatus.(12) Secretory vesicle.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m