The Endoplasmic Reticulum
22.01
Diposting oleh Melany Christy
The endoplasmic reticulum is an extensive network of membranes composed of both regions with ribosomes and regions without ribosomes.
Endoplasmic Reticulum
What are their distinguishing characteristics?
There are two regions of the ER that differ in both structure and function. One region is called rough ER because it has ribosomes attached to the cytoplasmic side of the membrane. The other region is called smooth ER because it lacks attached ribosomes. Typically, the smooth ER is a tubule network and the rough ER is a series of flattened sacs.
The rough ER manufactures membranes and secretory proteins. In leukocytes (leuk-) the rough ER produces antibodies (anti-). In pancreatic cells the rough ER produces insulin. The rough and smooth ER are usually interconnected and the proteins and membranes made by the rough ER move into the smooth ER to be transferred to other locations.
The smooth ER has a wide range of functions including carbohydrate and lipid synthesis. It serves as a transitional area for vesicles that transport ER products to various destinations. In liver cells the smooth ER produces enzymes that help to detoxify certain compounds. In muscles the smooth ER assists in the contraction of muscle cells and in brain cells it synthesizes male and female hormones.
There are two regions of the ER that differ in both structure and function. One region is called rough ER because it has ribosomes attached to the cytoplasmic side of the membrane. The other region is called smooth ER because it lacks attached ribosomes. Typically, the smooth ER is a tubule network and the rough ER is a series of flattened sacs.
The rough ER manufactures membranes and secretory proteins. In leukocytes (leuk-) the rough ER produces antibodies (anti-). In pancreatic cells the rough ER produces insulin. The rough and smooth ER are usually interconnected and the proteins and membranes made by the rough ER move into the smooth ER to be transferred to other locations.
The smooth ER has a wide range of functions including carbohydrate and lipid synthesis. It serves as a transitional area for vesicles that transport ER products to various destinations. In liver cells the smooth ER produces enzymes that help to detoxify certain compounds. In muscles the smooth ER assists in the contraction of muscle cells and in brain cells it synthesizes male and female hormones.
Smooth Endoplasmic Reticulum
The space inside of the ER is called the lumen. The ER is very extensive and is continuous with the nuclear envelope. Since the ER is connected with the nuclear envelope, the lumen of the ER and the space inside the nuclear envelope are part of the same compartment.
This entry was posted on October 4, 2009 at 12:14 pm, and is filed under
biology,
cell anatomy
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