1. Cell Membrane Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains

2. Membrane structure  Semi-Permeable  Selectively Permeable  Amphipathic~ hydrophobic & hydrophilic regions  Fluid Mosaic Model

3. Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains The Structure of the Cell Membrane

4. Membrane structure  Phospholipids~ membrane fluidity  Cholesterol~ membrane stabilization and fluidity  “Mosaic” Structure~  Integral proteins~ transmembrane proteins  Peripheral proteins~ surface of membrane proteins  Membrane carbohydrates ~ cell to cell recognition;

5. Video 1

6. Random movement results in  Solution – mixture of solute and solvent  Solute – substance being dissolved  Solvent – substance dissolving solute l Living Things (Universal Solvent)-Water

7. Membrane traffic  Passive transport~ diffusion of a substance across a biological membrane (NO ENERGY) [] = concentration  Diffusion~ the overall movement of particles from a region of high [] to an area of low [] l Osmosis~ the diffusion of water across a selectively permeable membrane

8. Results of Diffusion  Dynamic equilibrium l Once diffusion has evenly distributed the solute throughout the solvent; movement of particles continues with no change in []  Homeostasis l Preservation of equilibrium

9. Diffusion depends on [] gradient  [] gradient: the difference in [] of a substance across space  Diffusion is said to move down a [] gradient  Diffusion continues until there is NO [] gradient  Ex: O 2 diffuses into oxygen depleted blood

10. Diffusion Small molecules like WATER, OXYGEN, AND CARBON DIOXIDE can move in and out freely. Large molecules like PROTEINS AND CARBOHYDRATES CANNOT Charged IONS CANNOT

11. Video 2 Osmosis

12. Osmosis~ the diffusion of water across a selectively permeable membrane

13. Questions  Osmosis is the diffusion of _______ across a cell membrane.  Osmosis and Diffusion are both types of __________ transport.  Passive transport does or does not require energy?  Small molecules can not move across freely. T or F  Large molecules can move freely. T or F

14. Three Different Types of Solutions  Isotonic Solution  Hypotonic Solution  Hypertonic Solution

15. Isotonic Solution  The solute outside the cell is equal in concentration to the solute in the cell.  The cell retains its shape.  water moves equally in both directions

16. Hypotonic Solutions  Solution outside the blood cell contains a lower [] of solute than inside of the cell.  Water will diffuse in. l cell will lyse (burst).  Animal cells - cytolysis.  Plant cells do not burst- turgur pressure— grocers use this idea

17. Cells in a Hypotonic Solution

18. Hypertonic Solutions  The solution outside the cell has a higher [] of solute than inside of the cell.  Water will diffuse out of the cell, l causing the cell to shrink l or crenate  Why should you not salt meat before cooking? CRENATIONPLASMOLYSIS

19. Cells in a Hypertonic Solution

20. In what type of solution would these cells be found?

21. Water balance Summary  Osmoregulation ~ control of water balance  Hypertonic ~ higher concentration of solutes  Hypotonic ~ lower concentration of solutes  Isotonic ~ equal concentrations of solutes

22. Water balance Summary  Osmoregulation ~ control in cells with cell walls :  Turgid (very firm) - Hypo  Flaccid (limp) - Iso  Plasmolysis~ Hyper l plasma membrane pulls away from cell wall

23. Plasmolysis Turgidity

24. Other Ways to Transport Molecules Across the Plasma Membrane Selective Transport

25. Review Covered Passive Transport OO smosis DD oes it require energy? NN O!!! DD iffusion DD oes it require energy? NN O!!!

26. Osmosis  What is osmosis?  The movement of ___________ across the cell membrane.  Is it the movement of any other substance?  NO!!!! WATER

27. Diffusion  Mixing of two substances by the random motion of molecules.  Molecules move from a region of high concentration to an area of low concentration.

28. How do other molecules cross the cell membrane???  Selective Transport l Facilitated Diffusion (Another Passive Transport) l Active Transport Protein Pumps Endocytosis Exocytosis

30. Selective Transport  There are two types of selective transport l Facilitated Diffusion DOES NOT require the use of energy l Active Transport DOES require the use of energy

31. High Concentration Low Concentration Cell Membrane Glucose molecules Protein channel Facilitated Diffusion

32.  Does facilitated diffusion require the use of energy?  NO!!!!  It uses a [] gradient to transport molecules  The molecules move from an area of high [] to an area of low []  Most SUGAR molecules pass across the cell membrane by this method of transport

33. Carrier Proteins Carry Molecules Across the Membrane  Good Example - transport of Glucose into the Cell

35. Active Transport  Does active transport require the use of energy?  YES!!!  It uses ATP  Transports against the [] gradient.  Low to High []  Sodium Potassium Pump, Endocytosis and Exocytosis

36. Molecule to be carried Molecule being carried Energy Active Transport

37. Active Transport: Sodium Potassium Pump  Move Sodium out of the cell  Move Potassium into the cell  Uses energy (ATP)  Causes the protein to change shape  Move against a [] gradient

38. Sodium Potassium Pump

39. Bulk Transport-Active  Endocytosis l Pinocytosis l Phagocytosis  Exocytosis

41. Endocytosis  During ENDOCYTOSIS the Cell Membrane folds into a POUCH (Vescicle) that Encloses the Particles.

42. Two Types of Endocytosis: Pinocytosis and Phagocytosis  PINOCYTOSIS ---" CELL DRINKING “—Small Particles  PHAGOCYTOSIS---- " CELL EATING “-Large Particles

43. Treatments

44. Exocytosis  EXOCYTOSIS is the opposite OR reverse of ENDOCYTOSIS.  EXOCYTOSIS, wastes and cell products leave the cell.

46. Specialized Transport Summary  Transport proteins  Facilitated diffusion~ passage of molecules and ions with transport proteins across a membrane down the [] gradient  Active transport~ movement of a substance against its [] gradient with the help of cellular energy

47. Elaborate  Cell Membrane Bubbles  Cellular Transport Flow Chart