1. DAY 3

2. Facilitated Diffusion
Facilitators (teachers) in school help/assist
Facilitated basketball shot – assists the basket
During facilitated diffusion transport proteins help substances diffuse through the cell membrane.
Two types of facilitated transport proteins:
Channel proteins
Carrier proteins

3. Facilitated Diffusion Video

4. Transport Proteins Video

5. Channel Proteins
Ions, sugars, and amino acids can diffuse through the cell membrane through channel proteins.
These proteins aka pores serve as tunnels through the lipid bilayer.
Each tunnel allows for a specific substance to diffuse through it. This substance has a specific size and charge.

6. Channel – tunnel

7. Carrier Proteins- hand
Transport substances that fit within their binding site.
A carrier protein binds to a specific substance on a specific side of the cell membrane.
This binding causes the substance to change shape.
As the shape changes the protein is moved across the membrane and release on the other side.
This is enzyme activation across the membrane

8. Carrier – Hand

9. Channel and Carrier Proteins
Videos
Channel and Carrier Proteins

10. Osmosis Diffusion across a selectively permeable membrane.
Osmosis allows cells to maintain water balance as their environment changes.
(what is maintaining an internal environment called?)
Osmosis allows for water molecules to move down the concentration gradient to create an equilibrium between the cell and the external environment. – Basically the diffusion of H20

11. Water Channels
Polar water molecules do not diffuse directly across the bilayer.
The cell membrane contains channel proteins that only water can pass through.
Osmosis in cells is a type of facilitated diffusion.

13. Osmosis across a cell membrane
Osmosis Video
Osmosis in a beaker
Osmosis across a cell membrane

14. Activity
In class with a partner compare, contrast and create a chart for these passive transport methods.
Channel
Carrier
Osmosis
While you do it we can listen to these songs
Cell transport SONG
Osmosis Song with Mr. W.