1. Cell Membrane Pumps and Vesicle Transport
Active Transport
Cell Membrane Pumps and
Vesicle Transport
1. sodium-potassium pump
2.exocytosis
3. endocytosis

2. Movement of materials AGAINST the concentration gradient from LOW concentration to HIGH concentration.
requires the cell to use the energy molecule
- adenosine triphosphate (ATP)

3. Cell Membrane Pumps
Involve carrier proteins called cell membrane pumps to move materials against the concentration (UP concentration gradient) uses ATP (energy)
- similar to the steps of facilitated transport
(use of protein bridge)
- results in electrical impulses across nerve cells
- Sodium-Potassium Pump

4. Vesicle Transport
Some substances (ie. food) are TOO BIG to pass through membrane OR large quantities need to pass through the cell
These situations use vesicle transport
Endocytosis (entering the cell)
Exocytosis (exiting the cell)

5. Endocytosis
Cells ingest external fluid, macromolecules & large particles (including other cells)…
External materials are enclosed by part of the cell membrane, forming a pouch…
The pouch pinches off cell membrane & becomes a membrane bound organelle called  a vesicle…
Vesicles can fuse with lysosomes to digests contents!
Two kinds of Endocytosis:
Phagocytosis – movement of large particles or whole cells.
*Possible feeding method, or a method of defense to destroy
bacteria/viruses!!
2. Pinocytosis – transport of solutes or liquids

6. Phagocytosis (cartoon animation)
Pinocytosis
(cartoon animation)
Phagocytosis (cartoon animation)

7. Phagocytosis taking place in cells under a microscope

8. Endocytosis

9. Exocytosis reverse of endocytosis
Vesicles in cytoplasm fuse with cell membrane and RELEASE their contents into the external environment OUTSIDE the cell
Used to release large molecules such as proteins packaged by the Golgi apparatus (organelle in the cell)
Used in nervous
& endocrine system to
control activities in
other cells.

10. Exocytosis

11. Endocytosis & Exocytosis

12. Endocytosis