1. Cell Transport

2. Cell Communication Chemicals in blood stream
Receptor protein responds to signal molecule
Permeability change
Enzyme activation
Second messenger

3. Homeostasis Transport of materials across the membrane
Passive transport
Active transport
Transport proteins
Channel
Carrier

4. Passive Transport Diffusion
Movement of molecules from high concentration to low concentration
Kinetic energy
Equilibrium
No energy needed

5. Diffusion Across the Membrane
Simple diffusion
Move freely across the membrane
Small nonpolar molecules (O2 and CO2)

6. Facilitated Diffusion
Aid in the movement of molecules across the membrane
Carrier proteins
Channel proteins
Specific ions or molecules
Osmosis
Diffusion of water molecules
Polar molecules so channel proteins are used

7. Osmosis Explained
Solution is made up of solute (ex. sugar) and solvent (liquid).
Flow of water molecules depends on the concentration of the solutes on both side of the cell membrane

8. 3 Solutions
Hypotonic
Hypertonic
Isotonic

9. Hypotonic Solute (sugar) is lower outside of the cell than inside
Water moves into the cell
Cytolysis

10. Hypertonic Solute is higher outside of the cell than inside
Water moves out of the cell
Plasmolysis

11. Isotonic Solute is equal inside and outside of cell
Equal movement of water molecules

12. Carrier Protein

13. Carrier Protein Molecule binds to specific protein
Protein changes shape
Shields molecule from hydrophobic interior of cell membrane
Releases molecule on other side
Protein returns to original shape

14. Active Transport Requires energy from the cell
Moves material against the concentration gradient (upstream)
Cell membrane “pumps” (Carrier Proteins)
Vesicles

15. Sodium – Potassium Pump

16. Vesicles
Endocytosis

17. Exocytosis