external image membranecoat.jpgCell Membrane

"The cell membrane is probably the most multifunctional cellular structure"- Ivy Rose
@DatCellMembrane
external image cellmembrane.gif
The Best Rap of all Time
Cell Membrane Rap

Cell Membrane Functions:


  1. Mechanical Structure
  • Encloses the Cell- The membrane maintains the physical integrity of the cell by enclosing the cytoplasm and ALL of the organelles inside
  • Forms a protective barrier between the inside of the cell and the harsh environment outside of it
  • It physically separates the intracellular components from the extracellular components
  • Cytoskeleton- Cell membrane helps hold the cytoskeleton in place
  • Extracellular Matrix- Interacts with the cell membranes of other cells to form plant and animal tissues
  • Protection- Protects the cell from harmful chemicals and from the loss of important biological macromolecules which are he in the cell's membrane
2. Selective Permeability
  • The structure of the cell membrane allows only certain particles to enter and exit the cell
3. Active Transport
  • The cell membrane can allow some molecules to move against the concentration gradient
4. Bulk Transport
  • allows for bulk transport into (endocytosis) and out of (exocytosis) the cell
5. Communication
  • Uses proteins called "surface protein markers" to identify the cell
  • These proteins include:
    • hormones
    • neurotransmitters
    • immune proteins
  • The membrane also houses receptor sites to identify these markers

Cell Membrane Structure:

Cell membranes are made out of glycerophospholipids. These molecules are composed of glycerol, which is a phosphate group, and two fatty acid chains. They are by far the most abundant lipids in cell membranes. Their unique geometry causes them to aggregate into bilayers without any energy input. Lipids account for about half of the mass of cell membranes. Cholesterol molecules account for about 20% of the mass.
More About Cell Membrane Structure

Cited Resources:
"Functions of the Cell Membrane." Cell Membrane Function. Ivy Rose, n.d. Web. 5 Dec. 2013.<http://www.ivy-rose.co.uk/Biology/Cells/Cell-Membrane-Function.php>
"Cell Membranes." Nature.com. Nature Publishing Group, n.d. Web. 9 Dec. 2013.<http://www.nature.com/scitable/topicpage/cell-membranes-14052567>
"Membranes Organise Cellular Complexity." Learn Genetics. The University of Utah, n.d. Web. 8 Dec. 2013.<http://learn.genetics.utah.edu/content/begin/cells/membranes/>
"Fluid Mosaic Model of Membrane Structure and Function." Infoplease. Infoplease, n.d. Web. 10 Dec. 2013.<http://www.infoplease.com/cig/biology/fluid-mosaic-model-membrane-structure-function.html>
"Cell Membrane Overview." Boundless. N.p., n.d. Web. 9 Dec. 2013. <https://www.boundless.com/biology/the-plasma-membrane/cell-membranes-and-the-fluid-mosaic-model--2/cell-membrane-overview/>.

http://www.geol.umd.edu/~tholtz/G331/lectures/331arche.html (First Picture, Temporary)