1. Cellular Transport

2. What property allows the cell membrane to maintain homeostasis?
Cell membranes are selectively permeable: they let some molecules in and keep other molecules out.

3. Two Types of Cellular Transport
Passive Transport
cell does not use energy
Active Transport
cell uses energy
high
low
Weeee!!!
high
low
This is gonna be hard work!!

4. Passive transport characterisitics
Molecules move randomly
Molecules move from an area of HIGH concentration to an area of LOW concentration.
The cell spends NO ENERGY for the particles to move

6. 3 Types of Passive Transport
Simple Diffusion
Facilitated Diffusion
Osmosis

7. Simple Diffusion Animation
random movement of particles from high concentration low concentration.
diffusion continues until equilibrium is reached.
EX: gases, small particles

8. Simple Diffusion Animation
3 Factors that affect the rate of diffusion
Size of particles (permeability)
Concentration of particles
Temperature

9. 2) Facilitated Diffusion
diffusion of larger molecules through transport proteins found in the membrane
Transport proteins can be protein carriers or channels
Transport proteins are specific – they select only certain molecules to cross the membrane
EX: glucose, charged ions
Facilitated diffusion (Channel Protein)
Facilitated diffusion (Carrier Protein)

10. Facilitated Diffusion: Channel Proteins
Talk to a Partner

11. Facilitated Diffusion: Carrier Proteins
Talk to a Partner

12. 3) Osmosis Special case of diffusion
Diffusion of WATER through a selectively permeable membrane
Water moves from high water concentration area, to low water concentration area
Water moves freely through pores.
Solute (green) too large to move across.

13. Turn to a Partner Explain 3 characteristics of passive transport &
Describe each of the 3 types of passive transport

14. Questions??

15. Diffusion or Osmosis??
The student sitting next to you just came from gym class and forgot to shower

16. Diffusion or Osmosis??
One way to get rid of slugs in your yard is to sprinkle salt on them so they lose water and shrivel up.

17. Diffusion or Osmosis??
It’s the end of class, and the girl sitting in front of you just sprayed perfume so she could impress the guy in her next class

18. Diffusion or Osmosis??
Anthony sprays water on the veggies in the produce section to “plump them up”

19. Now we’ll talk about 3 situations in which osmosis occurs What type of transport is osmosis?

20. VOCAB
_____________ = substance that is dissolved in a solvent to make a solution
_____________ = substance in which a solute is dissolved
SOLUTE
SOLVENT

22. 1) Hypotonic Solution
The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute; High water)
Result: Water moves from the solution, to inside the cell: Cell Swells and bursts open (cytolysis)!

23. Think-Pair-Share
The animal cell will burst in a hypotonic solution, but the plant cell will not.
What organelle prevents the plant cell from bursting when in a hypotonic solution?

24. VACUOLES store WATER OSMOTIC (turgor) PRESSURE
OSMOTIC (turgor) PRESSURE
_____________________________
Pressure exerted by the movement of water during osmosis in plants

25. How Organisms Deal with Osmotic Pressure
A protist like paramecium pumps water out through a contracting vacuole
Kidneys keep the blood isotonic by removing excesss and water.
Paramecium (protist) removing excess water video

26. 2) Hypertonic Solution
The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute; Low water)
shrinks
Result: Water moves from inside the cell, to the solution: Cell shrinks (Plasmolysis)!

27. 3) Isotonic Solution
The concentration of solutes in the solution is equal to the concentration of solutes inside the cell.
Result: Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium)

28. B C A What type of solutions are these cells in? Hypertonic Isotonic
Hypertonic
Isotonic
Hypotonic

29. Think-Pair-Share
An IV is a direct infusion of liquid substances into a vein. Why would it be dangerous to give a person an IV infusion of distilled water?
What about 90% salt solution?

30. Passive Transport Animation

32. Active Transport (Low  High) cell uses energy
actively moves molecules to where they are needed
Movement from an area of low concentration to an area of high concentration
(Low  High)
Three Types:

33. Active Transport
Protein Pumps
Endocytosis
Exocytosis

34. Protein changes shape to move molecules: this requires energy!
Sodium Potassium Pumps (Active Transport using proteins)
1) Protein Pumps
transport proteins that require energy to do work
Example: Sodium / Potassium Pumps are important in nerve responses.
Protein changes shape to move molecules: this requires energy!

36. Endocytosis: taking bulky material into a cell Uses energy
Cell membrane folds around food particle pulling it into the cell
“cell eating”
forms food vacuole & digests food
This is how white blood cells eat bacteria!

37. Two Types
1) Phagocytosis (particles)
2) Pinocytosis (liquid)

38. Endocytosis & Exocytosis animations
forces material out of cell in bulk
membrane surrounding the material fuses with cell membrane
Cell changes shape – requires energy
This is how products, such as hormones, are released from cells
Endocytosis & Exocytosis animations

39. Exocytosis

40. Active Transport Review
Sodium-Potassium Pump
Endocytosis & Exocytosis

41. Turn to a Partner Explain 3 characteristics of active transport is &
Describe each of the 3 types of active transport

42. How Would You Answer?

43. Passive or Active Transport?

44. Passive or Active Transport?

45. Passive or Active Transport?

46. Which of the following is NOT a type of passive transport?
A. diffusion B. osmosis C. endocytosis D. facilitated diffusion

47. The movement of chloride ions from an area where chloride is concentrated to an area where chloride is less concentrated is which of these? a. diffusion b. active transport c. osmosis d. exocytosis

48. In an isotonic solution there would be:
a. no net movement of water b. net movement of water into the cell c. net movement of water out of the cell d. bursting of the cell

49. When a cell bursts due to osmosis, it is in a solution that is: a
When a cell bursts due to osmosis, it is in a solution that is: a. hypertonic b. isotonic c. hypotonic d. either A or C

50. Which way will the water move?
5% NaCl
95% H2O
solution
3% NaCl
97% H2O
Red Blood Cell

51. Which way will the water move?
3% Na
97% H2O
solution
3% Na
97% H2O
Red Blood Cell

52. Which way will the water move?
1% Na
99% H2O
solution
3% Na
97% H2O
Red Blood Cell

54. Cornell Summary for Cellular Transport
Passive Transport
Three characteristics
Three examples
Active Transport
Three characteristics
Three examples