http://www.usd.edu/~bgoodman/Membrane.htm
The cell membrane is one of the many organelles that a cell contains. All cells of mammals hold a nucleus surrounded by a nucleus membrane. It also contains cytoplasm surrounded by a cell membrane. The function of the cell membrane is to decide which molecules can or cannot enter the cell. Without the cell membranes, molecules that could potentially be dangerous to humans systems could enter the cells. This would not be good to say the least.
The cell membrane actually regulates the molecules by making sure that only the molecules who can go through the phospholipid bilayer (fat) will enter the cells. This creates a system that gets rid of the harmful products that cannot be used and accepts the healthy products that the bodies will put to use.
The cell membrane is made up of three parts, phosholipids which are magenta and green , the proteins which are orange and red, and the carbohydrates which are black. In more detail, the cell membrane is made up of various phospolipid molecules, or fats, that contain different large globular protein molecules hanging in them. The lipd bilayer in the cell membrane basically is the outer layer, or more specifically, two layers of phospolipids. This lipid bilayer is formed due to the phospholipids chemical structure. Due to the fact that the cells are constantly exposed to water, the phospholipids form a double layer. In this structure, the heads are pointed towards the water and the tails are in the opposite direction, away from the water. Proteins attach to the bilayers to complete the structure. It is not unusual for carbohydrates, or sugars, to attach to the cell membrane phospolipids and proteins.
-----Key Facts-----
1. Serves as "gateway + barrier for cell"
2. Made up of phospholipids and proteins.
3. The cell membrane isolate's the contents of the cell from the external enviroment.
4. The cell membrane regulate's the exchange of vital substances between the content of the cells and it external enviroment.
5. Finally, it communicates with other cells to help the body function.
6. It is extremely thin (you could stack 10,000 plasma membranes to equal the thickness of a piece of paper).
-----Pictures-----
1. Picture of actual cell membrane!!!
----Bibliography----
1. Ireland, Patrick. "The Cell Membrane." The Cell Membrane Headquarters. 6, Feb.00
2. Audesirk, Teresa. "Biology, Life on Earth." 1999
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