1. Ch 4- Cells and Their Environment 4.1: Passive Transport 4. 2: Active Transport Red & white blood cells in arteriole - SEM

2. The plasma membrane is the edge of life. All cells have a plasma membrane. All cells have a plasma membrane. It enables & maintains an internal environment of the cell that is different from its surrounding external environment. It enables & maintains an internal environment of the cell that is different from its surrounding external environment. Is selectively permeable, it controls the traffic of molecules into and out from the cell. Is selectively permeable, it controls the traffic of molecules into and out from the cell.

3. All told, each one of us has enough membranes in our body to cover about 75 soccer fields!

4. Map of molecules that can go through cell membrane. -Some can go through w/o using energy -Passive -Some need to use energy to get through -Active

5. Substances move IN & OUT of the cells by 2 ways- 1.Active transport – requires ENERGY 2.Passive transport – NO ENERGY

6. Membrane transport animations Membrane transport animations

7. Diffusion and Osmosis Passive Transport - movement of substances across the cell membrane without the use of energy by the cell. Concentration - A difference in the concentration of a substance across a space is called a concentration gradient. 4.1 Passive Transport

8. Diffusion -movement of a substance from Diffusion -movement of a substance from HIGH concentration to LOW concentration. HIGH concentration to LOW concentration. Low High

11. Osmosis- diffusion of free water molecules across a semi- permeable membrane. Osmosis HIGH LOW

13. Solutions What is a solution? What is a solution? a mixture in which one or more substances are evenly distributed in another substance. Solution: a mixture in which one or more substances are evenly distributed in another substance.

14. Solutions Solute: the matter that is being dissolved. Solute: the matter that is being dissolved. Solvent: the matter that is doing the dissolving. Solvent: the matter that is doing the dissolving. We are going to look at some solutions and relate it to cells in Biology.

15. Hypertonic Solutions: Hypertonic Solutions: contain a high concentration of solute relative to another solution (e.g. the cell's cytoplasm). contain a high concentration of solute relative to another solution (e.g. the cell's cytoplasm). –When a cell is placed in a hypertonic solution, the water diffuses out of the cell, causing the cell to shrivel.

16. Hypotonic Solutions: contain a low concentration of solute relative to another solution (e.g. the cell's cytoplasm). Hypotonic Solutions: contain a low concentration of solute relative to another solution (e.g. the cell's cytoplasm). –When a cell is placed in a hypotonic solution, the water diffuses into the cell, causing the cell to swell & possibly explode.

17. Isotonic Solutions: contain the same concentration of solute as an another solution (e.g. the cell's cytoplasm). Isotonic Solutions: contain the same concentration of solute as an another solution (e.g. the cell's cytoplasm). –When a cell is placed in an isotonic solution, the water diffuses into and out of the cell at the same rate. The fluid that surrounds the body cells is isotonic.

18. Animation More solute less solute Animation 2 - red blood cells

19. Know table 1 in book p.77

20. Explain

21. In plant cell

22. Crossing the Cell Membrane Most ions & polar molecules cannot pass across the cell membranes because they cannot pass through the nonpolar interior of the lipid bilayer. Most ions & polar molecules cannot pass across the cell membranes because they cannot pass through the nonpolar interior of the lipid bilayer. Transport proteins – called channels- provide passageways Transport proteins – called channels- provide passageways –Act as a bridge

23. Diffusion through ion channels- passive transport

24. Facilitated diffusion – passive transport CARRIER PROTEINS

25. Faciliatated Diffusion animation Faciliatated Diffusion animation

26. 4.2 Active Transport Objectives: Active transport vs passive transport. Describe the sodium-potassium pump. Endocytosis & exocytosis. Identify 3 ways that receptor proteins can change the activity of a cell.

27. Active Transport M ovement of a substance AGAINST the concentration gradient of the substance. requires cells to use ENERGY.

28. Sodium-Potassium Pump - In animal cells, this uses energy supplied by ATP to transport sodium ions out of the cell & potassium ions into the cell. Sodium-Potassium Pump - In animal cells, this uses energy supplied by ATP to transport sodium ions out of the cell & potassium ions into the cell. –Importance   Create conditions so can conduct electrical impulse

29. Sodium – Potassium pump: the cell pumps out 3 sodium ions and takes in 2 potassium ions.

30. Sodium potassum pump – Active transport Sodium potassum pump – Active transport

31. Active Transport Endocytosis & Exocytosis

32. Endocytosis - substances are moved into a cell by a vesicle that pinches off from the cell membrane.

33. Exocytosis -substances inside a vesicle are released from a cell as the vesicle fuses with the cell membrane.

34. Endo and Exocytosis animation

35. Cell-drinking – moves droplet of fluid Cell-eating – moves larger particles Receptor mediated – binds to certain nutrient molecule

36. Cell membrane - exo and endocytosis Cell membrane - exo and endocytosis

37. Mini-quiz Name ways of passive transport ? Name ways of passive transport ? –Diffusion –Ion channels –Facilitated diffusion Name ways of ACTIVE transport? Name ways of ACTIVE transport? –Sodium potassium pump –Endocytosis –Exocytosis

38. When the concentration of a substance is the same throughout a space, the substance is A. In equilibrium B. A hypertonic solution C. Undergoing passive transport D. Undergoing active transport

39. If a cell swells when placed in solution, the solution is A. Hypertonic B. Hypotonic C. Isotonic D. Saturated

40. Which of the following allows the cells to dispose of waste A. Endocytosis B. Exocytosis C. Osmosis D. Active transport

41. In diffusion a substance moves A. Against its conc. gradient B. From an area of lower conc to an area of higher conc C. Independent of its own conc D. Down its conc gradient

42. Facilitated diffusion A. Is driven by energy from ATP B. Is a type of active transport C. Employs receptor proteins D. Employs carrier proteins

43. The sodium potassium pump moves A. N a+ into cell & K + out B. N a+ out cell & K + in C. N a+ & K + in D. N a+ & K + out Na+ = sodium ions K+ = potassium ions

44. Passive Active Transport Passive Active Transport