1. Passive Transport

2. Goals Relate concentration gradient, diffusion and equilibrium Relate concentration gradient, diffusion and equilibrium Predict direction of water movement in and out of cells Predict direction of water movement in and out of cells Describe the importance of ion channels in passive transport Describe the importance of ion channels in passive transport Identify carrier proteins in facilitated diffusion Identify carrier proteins in facilitated diffusion

3. Passive Transport Random movement across a cell membrane that does not require any sort of energy Random movement across a cell membrane that does not require any sort of energy

4. Passive Transport How does this happen?----Imagine what happens when we place bouncing balls into one room and then open the door to another room? How does this happen?----Imagine what happens when we place bouncing balls into one room and then open the door to another room?

5. Passive Transport Step 1: Imagine many balls bouncing around a single room. Step 1: Imagine many balls bouncing around a single room. Step 2: Open a door to the adjoining room, letting balls out of the room and into the other Step 2: Open a door to the adjoining room, letting balls out of the room and into the other Step 3: Eventually the amount of balls per room will even out Step 3: Eventually the amount of balls per room will even out

6. Passive Transport Concentration gradient-A difference in the concentration of a substance from one spot to another Concentration gradient-A difference in the concentration of a substance from one spot to another

7. Passive Transport Equilibrium-When each side of the concentration gradient is equal in amounts of substances Equilibrium-When each side of the concentration gradient is equal in amounts of substances

9. Passive Transport In all solutions, the particles will move randomly like the balls in the model. In all solutions, the particles will move randomly like the balls in the model.

10. Passive Transport Once equilibrium is reached, particles still move around consistently, however we do not see the movement Once equilibrium is reached, particles still move around consistently, however we do not see the movement

11. Movement Cell membrane (Phospholipid Bilayer) Cell membrane (Phospholipid Bilayer) Selectively Permeable Selectively Permeable Membrane allows materials to dissolve through Membrane allows materials to dissolve through Nonpolar material repels ions, but small molecules can filter through Nonpolar material repels ions, but small molecules can filter through

12. Cell Membrane Help organisms maintain homeostasis by controlling the exit and entrance of materials Help organisms maintain homeostasis by controlling the exit and entrance of materials Passive transport-when organisms cross the membrane without any input of energy Passive transport-when organisms cross the membrane without any input of energy

13. 1. The activities of a cell depend on the materials that enter and leave the cell. 2. To stay alive, a CELL MUST EXCHANGE Materials such as Food and Waste With Its ENVIRONMENT. 3. These materials must cross the Cell Membrane.

15. 4. Small molecules like WATER, OXYGEN, AND CARBON DIOXIDE can move in and out freely. 5. Large molecules like PROTEINS AND CARBOHYDRATES CANNOT. 6. The Cell Membrane is SEMIPERMEABLE. 7. A SEMIPERMEABLE MEMBRANE OR SELECTIVELY PERMMEABLE ONLY ALLOWS CERTAIN MOLECULES TO PASS THROUGH.

16. Movement Diffusion-Movement of particles from an area of high concentration to an area of lower concentration Diffusion-Movement of particles from an area of high concentration to an area of lower concentration

17. Diffusion Simplest type of passive transport Simplest type of passive transport Driven by kinetic energy-energy of motion Driven by kinetic energy-energy of motion Rate depends on Rate depends on Temperature Temperature Diffusion is quicker at high temperatures Diffusion is quicker at high temperatures Type of molecule Type of molecule Smaller molecules diffuse faster Smaller molecules diffuse faster

18. Diffusion When molecules are dispersed EVENLY, there is no longer any Diffusion because there is no longer a Concentration Gradient. When molecules are dispersed EVENLY, there is no longer any Diffusion because there is no longer a Concentration Gradient. Diffusion will Eventually cause the Concentration of molecules to be the SAME Throughout the Space the Molecules Occupy. Diffusion will Eventually cause the Concentration of molecules to be the SAME Throughout the Space the Molecules Occupy.

19. Osmosis

20. Osmosis Osmosis-The Diffusion of water from an area of high concentration to low concentration across the cell membrane Osmosis-The Diffusion of water from an area of high concentration to low concentration across the cell membrane

21. Osmosis Like any other Diffusing Molecule, Water moves DOWN its Concentration Gradient Like any other Diffusing Molecule, Water moves DOWN its Concentration Gradient

22. Osmosis OSMOSIS OCCURS IN RESPONSE TO THE CONCENTRATION OF SOLUTES DISSOLVED IN WATER. OSMOSIS OCCURS IN RESPONSE TO THE CONCENTRATION OF SOLUTES DISSOLVED IN WATER.

23. Osmosis SOLUTES-DISSOLVED SUBSTANCES IN A SOLUTION. SOLUTES-DISSOLVED SUBSTANCES IN A SOLUTION. Cytoplasm is Mostly Water containing many dissolved solutes. Cytoplasm is Mostly Water containing many dissolved solutes.

24. Osmosis No two molecules can occupy the same space at the same time, so if there are more solutes there is less water No two molecules can occupy the same space at the same time, so if there are more solutes there is less water Water Moves from AREAS of LOW Solute Concentration to AREAS of HIGH Solute Concentration. Water Moves from AREAS of LOW Solute Concentration to AREAS of HIGH Solute Concentration.

25. Osmosis HYPERTONIC SOLUTION- HYPERTONIC SOLUTION- More Solute then solution More Solute then solution Concentration of solute is higher outside the cell then it is inside the cell Concentration of solute is higher outside the cell then it is inside the cell Water Moves out of the cell Water Moves out of the cell

26. the cell loses too much water, the cell will shrivel and shrink, it will die

27. Osmosis IN A HYPOTONIC SOLUTION- IN A HYPOTONIC SOLUTION- Less Solute and more solution Less Solute and more solution concentration of solute inside the cell is higher then the fluid out of the cell concentration of solute inside the cell is higher then the fluid out of the cell water will diffuse into the cell water will diffuse into the cell

28. In Hypotonic Solutions, WATER DIFFUSES INTO THE CELL until Equilibrium is established.

29. Osmosis Animal cells placed in distilled water (Hypotonic Solution) will swell and often burst because of Osmosis. Animal cells placed in distilled water (Hypotonic Solution) will swell and often burst because of Osmosis. Cytolysis-bursting of cells due to increased amounts of water Cytolysis-bursting of cells due to increased amounts of water

30. Osmosis Plant Cells do not burst because of their Rigid Cell Wall. Plant Cells do not burst because of their Rigid Cell Wall. TURGOR PRESSURE- pressure that Water molecules exert against the cell wall TURGOR PRESSURE- pressure that Water molecules exert against the cell wall

31. Osmosis In Isotonic solutions the inside and outside of the cells are equal In Isotonic solutions the inside and outside of the cells are equal

33. How does this relate to cells Single cell organisms and sea faring vertebrates have no problems in an isotonic solution Single cell organisms and sea faring vertebrates have no problems in an isotonic solution

34. Many cells function in a Hypotonic environment, such as Unicellular Freshwater Organisms. Water Constantly Diffuses into these Organisms Many cells function in a Hypotonic environment, such as Unicellular Freshwater Organisms. Water Constantly Diffuses into these Organisms

36. Facilitated Diffusion

37. Review- Review- Passive Transport involves no energy Passive Transport involves no energy Occurs down the gradient Occurs down the gradient Diffusion and Osmosis are passive Diffusion and Osmosis are passive

38. Facilitated Diffusion Molecules that cannot cross by passive transport are CARRIED across by CARRIER PROTEINS EMBEDDED IN the Cell Membrane.

39. Facilitated Diffusion 1. Carrier Proteins CHANGE SHAPE when Molecules ATTACH to them. 1. Carrier Proteins CHANGE SHAPE when Molecules ATTACH to them. 2. The Carrier Protein then releases the molecule and returns to its original shape

41. Facilitated Diffusion Facilitated Diffusion-THE USE OF CARRIER PROTEINS Facilitated Diffusion-THE USE OF CARRIER PROTEINS Facilitated Diffusion can help substances move Either INTO or OUT of a Cell Facilitated Diffusion can help substances move Either INTO or OUT of a Cell

42. Facilitated Diffusion Example- When cells transport Glucose into the Cell. Example- When cells transport Glucose into the Cell. Cells depend on Glucose for much of their Energy Needs. Cells depend on Glucose for much of their Energy Needs. Passive Passive

44. Facilitated Diffusion Ion Channels-Small passageways across the membrane which ions can diffuse Ion Channels-Small passageways across the membrane which ions can diffuse Sodium (Na+) and Potassium (K+) Sodium (Na+) and Potassium (K+)

45. Facilitated Diffusion Some ION CHANNELS are always open. Some ION CHANNELS are always open. Others have "Gates" that open to allow ions to pass or close to stop their passage. Others have "Gates" that open to allow ions to pass or close to stop their passage.

46. Facilitated Diffusion Gates are dependant upon the environment of the cell Gates are dependant upon the environment of the cell Three kinds of Stimuli that may open or close the Gates: Three kinds of Stimuli that may open or close the Gates: Stretching of the Cell Membrane Stretching of the Cell Membrane Electrical Signals Electrical Signals Chemicals in the Cytosol or External Environment Chemicals in the Cytosol or External Environment

47. Active Transport

48. Goals Compare active transport with passive transport Compare active transport with passive transport Describe the importance of the sodium- potassium pump Describe the importance of the sodium- potassium pump Distinguish between endocytosis and exocytosis Distinguish between endocytosis and exocytosis Identify three ways that receptor proteins can change the activity of the cell Identify three ways that receptor proteins can change the activity of the cell

49. Active Transport ACTIVE TRANSPORT-When cells use energy to move materials from an area of low concentration to high concentration ACTIVE TRANSPORT-When cells use energy to move materials from an area of low concentration to high concentration

50. Active Transport often involves CARRIER PROTEINS like those in Facilitated Diffusion Active Transport often involves CARRIER PROTEINS like those in Facilitated Diffusion

51. Cell Membrane Pumps Cell Membrane Pumps-Carrier proteins that act to move ions across the membrane during active transport Cell Membrane Pumps-Carrier proteins that act to move ions across the membrane during active transport

52. Cell Membrane Pumps IMPORTANT in MAINTAINING ION CONCENTRATION IN CELLS AND BETWEEN CELLS. IMPORTANT in MAINTAINING ION CONCENTRATION IN CELLS AND BETWEEN CELLS.

53. Cell Membrane Pumps SODIUM-POTASSIUM PUMPS- SODIUM-POTASSIUM PUMPS- IMPORTANT FOR MUSCLE CONTRACTIONS, IMPORTANT FOR MUSCLE CONTRACTIONS, TRANSMISSION OF NERVE IMPULSES TRANSMISSION OF NERVE IMPULSES THE ABSORPTION OF NUTRIENTS THE ABSORPTION OF NUTRIENTS

54. Cell Membrane Pumps SODIUM-POTASSIUM PUMPS -ANIMAL CELLS PUMP SODIUM IONS OUT, AND POTASSIUM IN SODIUM-POTASSIUM PUMPS -ANIMAL CELLS PUMP SODIUM IONS OUT, AND POTASSIUM IN

56. Cell Membrane Pumps In Plants, ACTIVE TRANSPORT enables roots to absorb nutrients from the soil In Plants, ACTIVE TRANSPORT enables roots to absorb nutrients from the soil Plant Nutrients are more concentrated inside the roots than in the surrounding soil Plant Nutrients are more concentrated inside the roots than in the surrounding soil WITHOUT ACTIVE TRANSPORT, NUTRIENTS would DIFFUSE OUT OF THE ROOTS WITHOUT ACTIVE TRANSPORT, NUTRIENTS would DIFFUSE OUT OF THE ROOTS

57. Why does this happen Takes away toxic sodium ions from the cell Takes away toxic sodium ions from the cell Maintains concentration gradient Maintains concentration gradient

58. Bulk Transport-Endocytosis and Exocytosis

59. Transport Bulk Transport-COMPLEX PROTEINS,that are too LARGE to cross the Cell Membrane, travel through the membrane via bulk transport Bulk Transport-COMPLEX PROTEINS,that are too LARGE to cross the Cell Membrane, travel through the membrane via bulk transport

60. 4 Types of bulk transport 4 Types of bulk transport Endocytosis Endocytosis Exocytosis Exocytosis Pinocytosis Pinocytosis Phagocytosis Phagocytosis

61. Endocytosis During ENDOCYTOSIS the Cell Membrane Folds into a POUCH that Encloses the Particles During ENDOCYTOSIS the Cell Membrane Folds into a POUCH that Encloses the Particles The Pouch pinches off INSIDE the Cell to form a VESICLE The VESICLE can then fuse with other Organelles (LYSOSOMES) or Release its contents into the Cytoplasm. The Pouch pinches off INSIDE the Cell to form a VESICLE The VESICLE can then fuse with other Organelles (LYSOSOMES) or Release its contents into the Cytoplasm.

63. PINOCYTOSIS AND PHAGOCYTOSIS ARE TWO TYPES ON ENDOCYTOSIS PINOCYTOSIS AND PHAGOCYTOSIS ARE TWO TYPES ON ENDOCYTOSIS PINOCYTOSIS IS SOMETIMES CALLED "CELL DRINKING PINOCYTOSIS IS SOMETIMES CALLED "CELL DRINKING PHAGOCYTOSIS -"CELL EATING" PHAGOCYTOSIS -"CELL EATING"

64. Exocytosis EXOCYTOSIS IS THE OPPOSITE OR REVERSE OF ENDOCYTOSIS EXOCYTOSIS IS THE OPPOSITE OR REVERSE OF ENDOCYTOSIS Exocytosis is when waste and cell products leave the cell Exocytosis is when waste and cell products leave the cell