1. Cell Membrane Pumps and Vesicle Transport
Active Transport
Cell Membrane Pumps and Vesicle Transport

2. Active Transport
Active transport - movement of materials AGAINST the concentration gradient from low concentration to high concentration
Requires the cell to use energy (ATP)
2 kinds:
1. membrane pumps
2. vesicle transports

3. 1. Cell Membrane Pumps
Involve carrier proteins called cell membrane pumps to move materials against the concentration (UP concentration gradient)
Similar to the steps of facilitated transport.
Results in electrical impulses across nerve cells
Ex. Sodium-Potassium Pump

4. large quantities need to pass through the cell
2. Vesicle Transport
Some substances (ex. Food) are too BIG to pass through membrane OR
large quantities need to pass through the cell
These situations use vesicle transport
Two kinds
Endocytosis
Exocytosis

5. Endocytosis
Cells ingest external fluid, macromolecules & large particles (including other cells)
External materials are enclosed by part of the cell, 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
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
Used in nervous
& endocrine system to
control activities in
other cells.

10. Exocytosis

11. Endocytosis & Exocytosis

12. Endocytosis