1. Active Transport
Chapter 7

2. Cell Membrane Pumps
A cell membrane pump moves ions across a cell membrane to maintain an electrical charge gradient
This process costs energy (ATP)
View an animation here of the Sodium/Potassium Pump:

3. The Na+/K+ Pump
The Na/K Pump moves 3 sodium ions outside a cell membrane while moving 2 potassium ions inside the cell
This changes the charge on the outside of the membrane (it becomes positive) and the inside (it becomes negative)
This charge changing process transmits nerve signals along a neuron (nerve cell)
Here’s another animation to look at:

4. The Na+/K+ Pump Here is how a membrane pump works:
A substance that wants to go in/out of the cell travels to the cell membrane
The substance binds to a receptor protein
The receptor protein changes shape to protect the substance from damage as it crosses the cell membrane
The receptor protein becomes a carrier protein and moves the substance out of/into the cell

5. The Na+/K+ Pump

6. Endocytosis
Endocytosis is a process where a cell brings a large particle into the cell
This costs energy!
Phagocytosis – movement of large solid particles into a cell
The particle brought in is called a “phagocyte”
Pinocytosis – movement of liquid or solutes into a cell

7. Endocytosis Endocytosis happens when:
A particle attaches to the outside surface of the cell membrane
The membrane surrounds the particle
The membrane pinches off inside the cell
Vesicle – the transport “container” created by the cell membrane
The membrane-surrounded particle moves into the cell

8. Endocytosis
Vesicle

9. Phagocytosis…the movie!
Phagocytosis Video:
Amoeba Phagocytosis Video:
Phagocytosis & Pathogens:

10. Exocytosis
Exocytosis – process where material exits a cell (uses energy!!)
Vesicle transports particle to the inside of the cell membrane
Vesicle fuses with membrane
Vesicle opens to release particle to the outside of the cell

11. Exocytosis
View the endo/exocytosis film here:

12. Quick Recap 2
Active Transport – movement of material in/out of a cell with an energy cost
Ex: large food molecules, invasive particles, ions, toxins & waste products
Examples of active transport include:
Endocytosis – bringing things into a cell; membrane creates a vesicle
Phagocytosis or pinocytosis
Exocytosis – bringing things out of a cell; membrane creates a vesicle
Membrane Pump – moves ions in/out of membrane to change overall charge on membrane and inside of cell

13. The End…
Bye-bye…now go study!!