1. 1 In the name of God

2. 1- membrane transport 2-osmosis M.Bayat PhD 2 Session 1

3. Cell membrane lipid bilayer (1925)RBC fluid mosaic model 3 Flip.flop Motion in lipid and pr Types of motions Laterally Rotation Flip,flop

4. cell membrane It is composed of proteins and lipids proteins, 55 % phospholipids, 25 % cholesterol, 13 % other lipids, 4 % carbohydrates, 3 % Lipid Barrier of the Cell Membrane Impedes Water Penetration. 4

5. phospholipids, 25 % 5 Control of fluidity by cholesterol?

6. 6 *Involved in signal transduction. Asymmetry in lipid distribution ?

7. Integral and peripheral pr 7

8. Cell Membrane Proteins. Membrane of myelinated axon 25%, membrane of mitochondria 75% Mean: 55% integral proteins (intrinsic) Channels (or pores) transporter enzymes Receptors Structural Pump peripheral proteins (extrinsic) Associate with the surface of the phospholipids' bilayer and predominantly by charge interactions with integral proteins Enzymes controllers of transport of substances through the cell membrane "pores." 8

9. Transport across the Cell Membrane Macromolecule transport : Material may cross membranes without passing through the molecules that make up the membrane 9

10. Endocytosis

11. Exocytosis 11

12. 12 Very large particles enter the cell by a specialized Function of the cell membrane called endocytosis. The principal forms of endocytosis are pinocytosis and phagocytosis. Pinocytosis means ingestion of macromolecules,such as most protein molecules that form vesicles of extracellular fluid. vesicle size is 100 to 200 nanometers Phagocytosis means ingestion of large particles,such as bacteria,whole cells,or portions of degenerating tissue.

13. ATP 13 ca ATP Ca Ingestion by the Cell - Endocytosis

14. The transport of molecules through membranes by diffusion, and Protein- mediated transport processes 14

15. 15 Carrier mediated transport Carrier mediated diffusion = facilitated diffusion

16. 16

17. 17

18. Molecular transport from membrane Reflection coefficient

19.  Brownian motion. Simple diffusion

20.  Fick's first law of diffusion states the following: √ MW and Radius Lipid solubility

21. 21 20 mg/L 10 mg/L AB If concentration of the substance in chamber A doubles the diffusion of The substance will change from 10 mg/h to:

22. simple diffusion from channel

23. Facilitated diffusion by carrier pr 23 Uniporters symporters antiporters brings glucose into the cell (GLUT2)

24. facilitated diffusion  Saturation  specificity  Inhibition

25. Primary active transport (Pump) Na/K ATPase in all the cells H ATPase Gastric parietal cells Renal distal tubules  Ca ATPase 25

26. Na/K pump & proton pump  http://highered.mcgraw- hill.com/sites/9834092339/student_view0/chapter38/cotransport__symport_and_anti port_.html http://highered.mcgraw- hill.com/sites/9834092339/student_view0/chapter38/cotransport__symport_and_anti port_.html  https://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120068/ bio05.swf::Proton%20Pump https://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120068/ bio05.swf::Proton%20Pump 26

27. P

28. 28 Na attachment = phosphorylation K attachment = Dephosphorylation

29. 29 The pump, while binding ATP, binds 3 intracellular Na+ ions.ATP ATP is hydrolyzed, leading to phosphorylation of the pump at a highly conserved aspartate residue and subsequent release of ADP.hydrolyzedphosphorylationaspartateADP A conformational change in the pump exposes the Na+ ions to the outside. The phosphorylated form of the pump has a low affinity for Na+ ions, so they are released. The pump binds 2 extracellular K+ ions. This causes the dephosphorylation of the pump, reverting it to its previous conformational state, transporting the K+ ions into the cell. K+dephosphorylation The unphosphorylated form of the pump has a higher affinity for Na+ ions than K+ ions, so the two bound K+ ions are released. ATP binds, and the process starts again.

30.  Inactivation of the sodium-potassium pump will cause : 1. An increase in the intracellular volume 2. increase intracellular Na 3. Decrease intracellular K 4. Depolarize the membrane 5. inactivation of Na channel 6. decrease excitability 30

31. Secondary active transport(co transport) 31

33. Team work 33

34. Osmosis M.Bayat Ph.D 34

35. Water diffusion 35

36. Water osmosis Water Net diffusion = 0 osmotic 1 milliosmole per liter concentrationis = 19.3 mm Hg osmotic pressure. osmotic ally Active particle 106 8 8

37. Osm=c × n × Q C= molar concentration N=number of particle Q= osmotic coefficient 37 Calculation of Osmolarity 100 mmol CaCl2 100 ×3= 300 mosm 150 mmol NaCl 150 × 2= 300 mosm 280 mosm = iso-osmolar < 280 =hypo-osmolar > 280 = hyper-osmolar

38. 38

39. 39 osmotic coefficient × 19.3 ×

40. 40

41.  Iso-osmolar =300  Hyper-osmolar >300  Hypo-osmolar <300 41

42. 42 osmotic equilibrium? Tonicity

43. Mannnitol 43 H2O Mannnitol

44. 44

45. 45

46. 1.Which of the following is highly soluble in lipids: A.O2 B.N C. CO2 D. alcohol E. all 2.Which of the following enters the cell through protein channels: A. water B.O2 C.Na D. a&c 3.Which of the following enters the cell through carrier mediated diffusion: A.AA B.glucose C:hormones D: all 4. What is difference between primary active transport and secondary active transport? Glucose is cotransported into cell with………ion Cell cytosol concentration of calcium is …………times lower than outside The location of Calcium pump in …….,……..,…….. 46