1. 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. 2. Vesicle Transport  Some substances (ex. Food) are too BIG to pass through membrane OR large quantities need to pass through the cell large quantities need to pass through the cell  These situations use vesicle transport  Two kinds 1.Endocytosis 2.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: 1. 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)

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 http://www.maxanim.com/physiology/Endo cytosis%20and%20Exocytosis/Endocytosi s%20and%20Exocytosis.htmhttp://www.maxanim.com/physiology/Endo cytosis%20and%20Exocytosis/Endocytosi s%20and%20Exocytosis.htm

13. Closure Take a handout Write down –3 Facts you learned –2 questions you still have –1 opinion you now have (about this topic) Turn in on your way out!