Membrane Structure and Transport

Nota:

• 1.Lipid bilayer is a dynamic structure. 2. Protein can float in lipid 3. 

Nota:

• Protein molecules are dispersed and inserted individually into the lipid bilayer

1. Proteins

   Nota:

   • Act as electron carries
2. Lipids

   Nota:

   • increase fluidity and permeability
3. Cholesterol

   Nota:

   • regulates fluidity (less fluid in warm temperature , prevents solidifying in cool temperature)
4. Glycolipids
5. Glycoprotein

   Nota:

   • Recognition features

Nota:

• Absorption of Oxygen 

Nota:

• Movement of potassium and sodium ion in neurones

Nota:

•  HIGH WATER POTENTIAL to LOW WATER POTENTIAL  through a PARTIALLY PERMEABLE MEMBRANE

Nota:

• movement of particles across membrane against a concentration gradient through a biological pump

1. Endocytosis

   Nota:

   • bulk transport of material through membranes INTO the cell by infolding or extension of membrane
   1. Phogocytosis

      Nota:

      • the ingestion of BACTERIA or other material by phagocytes
   2. Pinocytosis

      Nota:

      • the ingestion of LIQUID into a cell by the budding of small vesicles from the cell membrane.
2. Exocytosis

   Nota:

   • bulk transport of material through membrane out of the cell by out folding or inverting the membrane.

Nota:

• Free KINETIC ENERGY of water molecule
• PURE WATER has highest water potential, 0.

Nota:

• Negative component of water potential 
• also known as "osmotic pressure" or "osmotic potential"

Nota:

• Usually Positive
• Hydrostatic pressure to which water is subjected.