1. Cell Transport
Ch. 8 pg

2. Homeostasis Homeostasis
Cells want to have a balance of nutrients and waste. Homeostasis is the cell’s ability to remain at a stable equilibrium.

3. Cell Membrane composed of 2 layers: called the phospholipid bilayer
A phospholipid is made of a phosphate head and lipid tails 3

4. Fluid Mosaic Model Pg. 293 in textbook
There is LOTS stuck inside the cell membrane!
Proteins, Carbohydrates, Lipids together form the ‘mosaic’

5. Cell Transport
The cell membrane is the organelle responsible for transport of gases, nutrients, and wastes into and out of the cell.

6. The substances that enter and leave the cell may be ions or molecules, or in some cases micro-organisms or other cells. These substances in a physical sense are particles, and behave according to The Particle Model of Matter.

7. Particle model of matter

8. Cell Transport
The Particle Model of Matter
Solid
Liquid
Gases

9. Cell Transport
The cell membrane is considered to be selectively permeable because it allows certain particles to pass through it, but not all particles.
This is called a semi-permeable membrane.

10. Cell Transport water demonstration Diffusion
Why can you smell bacon when cooking in the house?
Diffusion is the natural movement of particles from an area of high concentration to an area of low concentration. Since the particles are in constant motion they move until they are equally distributed throughout the room, resulting in a state of equilibrium.
Adding energy and increasing molecular movement (i.e. heat and stirring) can increase the rate of diffusion.
Diffusion can also occur in cells.
water demonstration

11. Cell Transport Diffusion
The difference in concentrations is called a concentration gradient, determining the direction the water or solute will flow. The cell membrane is the gate keeper, maintaining an equilibrium on either side of the cell favorable for the life processes.
Movement of materials through the process of diffusion is considered passive transport because no added energy is required for it to occur.

12. CONCENTRATION GRADIENT
What does this term mean??? 12

13. Cell Transport

14. Cell Membrane= GATEKEEPER14

15. EXAMPLE 15

16. Cell= OPEN SYSTEM 16

17. Cells= OPEN SYSTEM 17

18. Open System
The cell is an open system, therefore is always interacting and responding to the conditions of the environment.

19. OSMOSIS
Osmosis
Osmosis is the movement of water through a membrane in response to its concentration gradient.
The membrane is not permeable to the solute.
The membrane is permeable to water.
That is why it is called semi-permeable.

20. If the cell membrane is not permeable to the solute mixed with water, the water will pass through the semi-permeable cell membrane, leaving the solute molecules outside of the cell. This is the process of osmosis.
Osmosis is another form of passive transport.

21. http://www. google. ca/imgres 21

22. Experiment in a Bag
How does a ziploc bag with starch and iodine help us understand how a cell works?

23. What two substances caused a chemical reaction?
Based on your observations of a chemical reaction which substance moved? Which direction did the substance move? (In or out of the bag?)
Based on your observations, is the membrane permeable, semi- permeable or impermeable? Explain how you know.
Based on which substance was moving, would you call this movement diffusion or osmosis? Explain your answer.

24. Cell Transport
Tonicity describes the relative concentration of solutes in two solutions

25. Cell Transport Osmosis
To predict the direction in which a net movement of water will occur, the solute concentration must be compared.
Hypertonic ("hyper" means over) - The concentration of the solutes outside is higher than it is inside the cell. Therefore if the cell is put into this solution, water will leave the cell.
Plasmolysis is the shrinking of plant cells in a hypertonic solution
Crenation is the shrinking of animal cells in a hypertonic solution.

26. Cell Transport
Hypertonic

27. Cell Transport Osmosis
Isotonic ("iso" means equal) - The concentration of solutes outside the cell is equal to the inside of the cell. Therefore if the cell is put into this solution, there is no net movement of water molecules, just odd molecules moving in and out of the cell.

28. Cell Transport Osmosis
Hypotonic ("hypo" means under) - The concentration of solutes outside is lower than it is inside the cell. Therefore if the cell is put into this solution, water will enter the cell.

29. 29

30. Why is this wrong? 30

31. Lab
The Incredible Egg!

33. Cell Transport Facilitated Diffusion
There are two forms of protein mediated transport for those molecules that are soluble in water but not in lipids, and to cross the cell membrane.
Channel proteins create pores or channels through which small water-soluble particles are able to move. These molecules move in response to the concentration gradient.

34. CHANNEL PROTEINS 34

35. Cell Transport Facilitated Diffusion
Carrier proteins have the ability to attach to larger molecules that are not able to diffuse across the membrane.
The carrier protein changes shape and physically moves the molecules across the membrane and into the cell.

36. Once the molecules have been transported, the protein returns to its original shape.
This process is a called facilitated diffusion, which is the movement of substances in response to the concentration gradient but also requires the presence of the protein facilitator.
Both forms of protein mediated transport are examples of passive transport, because no added energy needed.

37. CARRIER PROTEIN 37

38. Cell Transport Active Transport
Active transport requires energy input to transport molecules. Active transport is necessary when protein carriers need to carry molecules across the concentration gradient, from areas of low concentration to areas of high concentration.
The energy required is produced in the mitochondrion through the process of cellular respiration and comes from the substances called adenosine triphosphate or ATP. A series of chemical reactions occurs first in the cytoplasm then in the mitochondrion, to break down glucose and produce the ATP.

39. ACTIVE TRANSPORT 39

40. 40

41. Cell Transport Endocytosis and Exoscytosis
When a molecule need to be taken in by the cell, but are too large to pass across the cell membrane, event with the help of protein carriers, the process of Endocytosis occurs.
Endocytosis is the process that occurs when a vesicle (a small temporary sac) forms around the particle and the cell membrane pinches off around it so that the vesicle is inside the cell. Figure C2.20a pg 281
Cytoplasm being extended
Particle engulfed by cell

42. 42

43. Cell Transport Endocytosis and Exoscytosis
When a molecule need secreted by the cell, but are too large to pass across the cell membrane, a vesicle surrounds the particle, then moves to the cell membrane and fuses with it. The vesicle then ruptures, releasing its contents into the surrounding area of the cell. This process of secretion is called exocytosis. Figure C2.20b pg. 281
Both exocytosis and endocytosis require energy from ATP for the rearrangement of the cell membrane.
A technical name for the vesicles is PINOCYTES.

44. Exocytosis 44

45. Cell Transport
Endocytosis and Exoscytosis
Endocytosis
Exocytosis

46. Web Concept Map

47. Review Cell membrane Diffusion Osmosis Channel Protein Carrier Protein
Passive Transport
Active Transport

48. Cell Membrane 48

49. The cell membrane is composed of two layers, what are they called?

50. Diffusion http://highered. mcgrawhill

51. Diffusion is the net movement of particles from concentration to concentration

52. http://highered. mcgrawhill

54. Hypotonic solution is:
A) Hypotonic solution is when the solution has a higher solute concentration relative to the cell. Water will move out of the cell.
B) Hypotonic solution is when the solution has a higher solute concentration relative to the cell. Water will move into the cell.
C) Hypotonic solution is when the solution has a lower solute concentration relative to the cell. Water will move out of the cell.
D) Hypotonic solution is when the solution has a lower solute concentration relative to the cell. Water will move into the cell.

55. Hypotonic solution is:
A) Hypotonic solution is when the solution has a higher solute concentration relative to the cell. Water will move out of the cell.
B) Hypotonic solution is when the solution has a higher solute concentration relative to the cell. Water will move into the cell.
C) Hypotonic solution is when the solution has a lower solute concentration relative to the cell. Water will move out of the cell.
D) Hypotonic solution is when the solution has a lower solute concentration relative to the cell. Water will move into the cell.

56. Practice Questions

57. CHANNEL PROTEINS 57

58. CARRIER PROTEIN 58

59. 59

60. Active transport requires energy, which is supplied in the form of
Active transport requires energy, which is supplied in the form of Energy that the cell needs is made in the organelle. The energy production is called:

61. Active transport requires energy, which is supplied in the form of ATP
Active transport requires energy, which is supplied in the form of ATP . Energy that the cell needs is made in the mitochondria organelle. The energy production is called cellular respiration.

62. Exocytosis 62

63. Exocytosis is when material (leaves or enters) the cell.
Endocytosis is when material (leaves or enters) the cell.

64. Exocytosis is when material leaves the cell.
Endocytosis is when material enters the cell.

65. PHAGOCYTOSIS
bio4fv/page/phago.htm
Phagocytosis is a type of endocytosis
The cell extends the cell membrane and engulfs the material. The cell uses phagocytosis when the material is TOO big to be transported in through endocytosis.

66. Homeostasis
Cells want to have a balance of waste, nutrients and energy. Homeostasis is the cell’s ability to remain at a constant state.

67. SIZE
Because cells want to exchange material efficiently they need to be a certain size.
Large cell=high volume and low surface area, which means LOTS will need to be transported across small surface
Small cell= low volume and high surface area, which means less will need to be transported across large surface

68. SIZE

69. SIZE What not have one GIANT cell? What’s advantage with multicelluar?
Survivor vs. teamwork???

72. Cell-> Tissue -> organ-> organ systems

73. APPLICATION HIV ‘infects’ the cell by endocytosis
If the receptors on the cells changed then HIV wouldn’t affect the cell

75. Application Insulin is released by exocytosis from pancreas cells
They travel through the bloodstream
Insulin attaches to receptor proteins allowing the cell to be activated
Carrier proteins allow for the facilitated diffusion of sugar into body cells
So… for people that can’t make insulin…

76. Application

77. Application Peritoneal Dialysis
-people with disfunctional kidneys can have peritoneal dialysis performed to filter their blood
-toxins move from a high concentration (blood) to low concentration (dialysate fluid)

79. Reverse Osmosis
-used when you need to remove unwanted particles from water
-moving water from low concentration to high concentration
-naturally want to go other way; therefore you need ENERGY!!

80. Application
Reverse Osmosis

81. Applications- pgs
Membrane Proteins and Disease- HIV
Transport of Protein Hormones-Insulin
Peritoneal Dialysis
Reverse Osmosis