Cell Membrane

Cell membrane:

• Complex 3D structure
• Makes up the exterior of the cell
  • In pictures, it looks like a 2D structure that surrounds the nucleus. 
• Main Functions: 
  • Protection
  • Establishing a Barrier
  • First barrier for unicellular organisms
  • Transportation
  • Communication
• Main component: phospholipid
  • @least 75% of a membrane is composed of phospholipids
  • Primary function
  • Protection by creating a barrier or cellular fence
  • Lipids are responsible for making the barrier
  • Are dimers (2 fatty acids)
  • Dehydration synthesis 
  • 1 water molecule for each fatty acid attached

Phospholipids : comprise the lipid bilayer, when is =  to a cellular fence.

• Cellular fence: create a barrier- establish an interior and exterior barrier

Protein Channels: allow for controlled small scale transport

• Channel is specific for ONE different molecule
• Equivalent to have different sized shape and size

Cell membrane is called the Fluid Mosaic Model 

Glycoproteins: participate in transport & communication

Cholesterol: because of its non-symmetrical shape it acts as a spacer. More space in the bilayer = increased fluidity. 

Main membrane functions linked with main membrane parts. 

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