1. 3.5 Passive Transport vs. Active Transport
Passive Transport: requires NO energy.
Diffusion (dialysis and osmosis)
Facilitated diffusion
Active Transport: requires energy
Active Transport
Endocytosis/Exocytosis

2. Diffusion and Osmosis require no energy (Passive Transport)

3. Passive Transport
Some molecules are too large to fit through the phospholipid bilayer. They can only diffuse through proteins. (This is still Passive Transport.)
Facilitated diffusion is diffusion through proteins in the cell membrane.
Example: glucose

4. Active transport occurs through protein pumps.
Active transport uses energy to move things against its concentration gradient.
Active transport occurs through protein pumps.
Energy allows the protein to change shape and pump molecules against the concentration gradient

5. Active Transport: Sodium/Potassium Pump
For Example:
For nerve cells to function properly, there must be a higher concentration of Na outside and higher concentration of K inside the cell

6. Sodium Potassium Pump
(See animation)

7. Endocytosis and Exocytosis
If the material is too large to move through the protein, it must enter/exit in a different way.
Endocytosis (material entering cell)
Examples: food into amoeba, white blood cells
Steps:
Material surrounded by cell membrane
Vesicle pinches off from cell membrane
Vesicle enters cell, contents are released
Empty vesicle digested by lysosome

8. Endocytosis

9. Moving material out of the cell.
Exocytosis
Exocytosis
Moving material out of the cell.
Examples: protein exported, nerve cells
Steps:
Material in the cell is packaged by the Golgi
Vesicle joins with the cell membrane
Contents are dumped outside the cell and the membrane closes back up

10. Exocytosis