1. Cellular Transport: Part Two
Getting In and Out of Cells
With Effort!!

2. Review: Passive Transport
Passive Transport does NOT use energy.

3. Three Types of Passive Transport
Diffusion: the movement of molecules from an area of high concentration to an area of low concentration
Osmosis: the diffusion of water across a selectively permeable membrane
Facilitated diffusion: diffusion with the help of a transport protein (gate)

4. Active Transport Active Transport Requires ENERGY
substances move from areas of low concentration (few molecules) to areas where the concentration is already high (lots of molecules)

5. Source of energy YOU NEED THIS ATP
Chemical energy stored in the molecule ATP
ATP→ADP + Phosphate + energy
YOU NEED THIS ATP

6. Energy Most of the ATP for cell transport is made in the mitochondria

7. Example Trying to walk against the crowd
Sodium ions are pumped out of cell
Potassium ions are pumped in

8. Endocytosis (“enter the cell”)
Endocytosis: Cell membrane surrounds particle and then pinches off inside the cell:
Forms a vesicle: storage “box” *

9. Examples One-celled organisms (amoeba) eat this way
White blood cells “eat” bacteria

10. Exocytosis (“exit the cell”)
Exocytosis: Vesicles inside the cell move to the cell membrane and merge. Contents of vesicle are released outside the cell.

11. Examples Hormones are released into the blood
Digestive chemicals are released into your stomach

12. And now you know… Getting things in and getting things out…
That’s what Cellular Transport is all about
And Now..
One more look at my favorite
ENDOCYTOSIS