Rough Endoplasmic Reticulum

Justine Kimball

The rough endoplasmic reticulum (rough ER) is a series of folded sheets and interlocking channels that form something that resembles a maze. The rough ER is located in the cytoplasm and its membrane is continuous with the nuclear membrane.

Audesirk, Teresa and Audesirk, Gerald.Biology. New Jersey: Prentice Hall, 1999.

Rough ER is called 'rough' because of its exterior coating of ribosomes. These ribosomes, scattered over the outside of rough ER, synthesize proteins. Because the ribosomes synthesize protein, including membrane proteins, the ER can synthesize itself (both protein and lipid parts.) Once synthesized, most of the synthesized membrane stays and forms new or replacement membrane. Some of the synthesized membrane, however, goes inward to replace nuclear membrane, or outward to form the Golgi complex, lysosomes, and the plasma membrane.

Ribosomes on the outside of rough ER also make the proteins that some secretory cells put out into their surroundings, including digestive enzymes and protein hormones. These proteins are synthesized by the ribosomes on rough ER and move into the channels of ER. They eventually accumulate in pockets which bud off into membrane sacs. These sacs are called vesicles and they carry protein cargo to the Golgi complex.

http://cellbio.utmb.edu/CELLBIO/rerlinks.htm

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Cool Links

http://www.brigadoon.com/~schaffer/biology/endoplas.html

http://cellbio.utmb.edu/cellbio/rer2.htm

http://www.cbc.umn.edu/~mwd/cell_www/chapter2/ER.html

Sources

Audesirk, Teresa and Audesirk, Gerald.Biology. New Jersey: Prentice Hall, 1999.