The Golgi Apparatus

By Tristram Arscott

In the late 19th century, Camillo Golgi, an Italian anatomist, described the Golgi complex, also referred to as the Golgi apparatus. The Golgi apparatus is located throughout the cell, especially near the nucleus. They are composed of six to seven flattened, membrane-bound sacs called cisternae, and separated by a narrow space in the form of a cup. The number of Golgi apparatus varies from 10 to 20 in each animal cell, but plant cells contain several hundreds.

The Golgi apparatus is used to store, package and distribute proteins and lipids made in the endoplasmic reticulum (the smooth endoplasmic reticulum synthesizes mainly lipids, and the rough endoplasmic reticulum synthesizes proteins for the most part). The proteins and lipids enter the apparatus through an opening in the concave side. They make their way through the stacks of cisternae, and leave through the convex end. Before leaving the Golgi apparatus, they are attached to a carbohydrate or lipid, and coated with a special membrane so they do not affect the cell. After leaving the Golgi apparatus, the proteins and lipids are sorted out and sent to their destinations. Vesicles also play an important role in the distribution of the proteins and lipids through the plasma membrane.

Another function of the Golgi apparatus is to manufacture polysaccharides. Polysaccharides are long chains of sugars made up of monosaccharides such as glucose, fructose, or galactose. Cells secrete these polysaccharides into their external environments (outside the cell). The polysaccharides produced by the Golgi apparatus are used in the mucus of animal cells. In plant cells, cellulose, an important polysaccharide for plant structure, is produced.

Click here to view this image's source and to
see a detailed outline of what happens in
the Golgi Apparatus.
This picture shows the cisternae, composing the Golgi
apparatus.

Click here to view a larger picture of a plant cell.
and to see where the Golgi bodies are located in the cell.

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Last updated: February 17, 2000

Bibliography:

1. Ferguson, John B. Sc.B., M.Phil., Ph.D. Professor of Biology, Division of Natural Sciences and Mathematics, Bard College. Director,Distinguished Scientist Lecture Series, Bard Center. http://encarta.msn.com/encarta/Contents.asp?z=2&br=0&pg=2&ti=0CCBD000 February 2000

2. "Cells-Golgi Bodies." http://www.dcn.davis.ca.us/~carl/Golgi.htm February 2000

3. "Golgi Bodies." Natural Toxins Research Initiative at Texas A&M University - Kingsville http://ntri.tamuk.edu/cell/Golgi.html February 2000

Plant Cell

http://encarta.msn.com/encarta/MediaMax.asp?z=2&br=0&pg=3&ti=042EA000&med=1&idx=59293