1. Membrane Transport

2. Membrane Transport • What are some substances commonly transported across membranes?

3. Membrane Transport • What are the three mechanisms used to move solute molecules across the membrane?

4. Simple Diffusion • What is involved in this transport process? • What can cross the plasma membrane via simple diffusion?

5. Simple Diffusion • How does osmosis differ from simple diffusion?

6. Simple Diffusion • What are the major factors that influence diffusion across a membrane?

7. Simple Diffusion • What specifically determines the rate of simple diffusion? vinward = PΔS P = permeability coefficient ΔS = concentration gradient

8. Simple Diffusion • What is the partition coefficient and how does it affect diffusion?

9. Facilitated Diffusion • How is facilitated diffusion different from simple diffusion?

10. Facilitated Diffusion • What do we know about transporters? • What is the difference between a transporter or carrier protein and a channel protein?

11. Facilitated Diffusion

12. Facilitated Diffusion • In what ways do transporters resemble enzymes? • What kinds of molecules are transported via facilitated diffusion?

13. Facilitated Diffusion • What do we specifically know about the transport of glucose in red blood cells?

14. Facilitated Diffusion • What is the difference between ion channels, porins and aquaporins?

15. Active Transport • How is active transport similar to and different from facilitated diffusion?

16. Active Transport • What is the difference between direct and indirect active transport?

17. Active Transport • How can we calculate the energy needed to transport uncharged molecules across a membrane? • ΔG = RT ln [S]inside/[S]outside free energy need to transport molecules from outside to inside of membrane

18. Active Transport • If the solute being transported has a charge how does that affect the energy requirement? • ΔG = RT ln [S]inside/[S]outside + zFVm z = charge on ion F = 23,062 cal/mol-V (Faraday constant) Vm = membrane potential – in volts Sum of concentration & charge gradients = electrochemical gradient

19. Active Transport • What are the four types of transport ATPases?

20. Active Transport • What do we currently know about the sodium-potassium pump?

21. Active Transport

22. Active Transport • Why is this sodium-potassium pump so important for animal cells?

23. Active Transport • Why is the Na+/glucose symporter an example of indirect active transport?

24. Active Transport

25. Active Transport • What does the bacteriodopsin pump do and where is it found?

26. Active Transport