1. “Materials move across the Cell’s membrane”
Section 2.3

2. Do Now What is the purpose of the cell membrane in a cell?
What goes in and out of our cells?
Why are our membranes important?

3. Objectives
To explain the different functions of the macromolecules in the plasma membrane.
To understand the process of diffusion.
To compare and contrast active and passive transport.

4. Membranes “Fluid Mosaic Model”
Proteins and other components are embedded like a mosaic

5. Membrane Components Phospholipids:
Gives the general structure of the membrane

6. Draw a phospholipid and label its parts!!

7. Membrane Components Proteins: allow bigger substances to pass through
Provide structure
Microtubules and microfilaments (Cytoskeleton)

8. Membrane Components
Cholesterol: helps maintain structure of phospholipids
prevents them from sticking together!

9. Membrane Components
Carbohydrates: receptors that send and receive signals.
Attached to glyolipids and glycoproteins

10. Do Now What is diffusion? What is osmosis?
How did you lab show osmosis happening?

11. Types of Transport across a cell membrane
Passive Transport
Active Transport
Vesicular Transport

12. Passive Transport Do NOT require energy
Go from an area of high concentration to an area of low concentration
“Go with the flow”

13. 3 Types of Passive Transport
Diffusion
Facilitated Diffusion
Osmosis

14. Diffusion
Molecules move from an area of high concentration to an area of low concentration .
Trying to create DYNAMIC EQUILIBRIUM. (The same in all areas)

15. Affected By… Heat- higher temp increases rate State of Matter
Solid- slow
Liquid- faster
Gas- fastest
Size and Concentration
Bigger= slower
More concentration = faster

16. Explain what’s happening…

17. Do NOW
Explain what happens when you put a sugar cube in your tea in regards to diffusion.

18. Objectives To understand how the process of Osmosis works.
To explain the different types of solutions
To compare and contrast endocytosis vs. exocytosis.

19. Facilitated Diffusion
the molecules need a “helper” or “facilitator” to allow them to cross the membrane when they are too big.

20. Osmosis
The flow of WATER from a high concentration to a low concentration
Occurs based on the types of solutions you are working with.

21. Solution
A) a mixture in which you cannot separate the components (ex: Kool aid)
i. solute: the substance being dissolved
Ex: kool aid powder
Ii. solvent: The substance doing the dissolving
Ex: water

22. Do Now
I like to make ice tea using ice mix and water. Identify the: 1. Solute: 2. Solvent: 3. Solution:

23. Isotonic Solutions
Same amount of solute inside the membrane as there is outside.
Cell in this solution: NOTHING 
Plant Cell
Blood Cell
11,397x

24. HYPERtonic Solutions
More solute, less water on the outside of the membrane.
Cell in this solution: shrinks/shrivels 
“Plasmolysis”
“Crenates”

25. HYPOtonic Solutions
Less solute, more water on the outside of the membrane.
Effect: cell swells or bursts! /

26. Do Now High or low Solute?
Cell in ________ Solution
Cell in ________ Solution
Cell in ________ Solution
H2O
H2O
H2O

27. Answer key! Write where there is high water and high solutes.
Cell in hypotonic Solution
Cell in isotonic Solution
Cell in hypertonic Solution
H2O
H2O
H2O

28. Do Now For the following examples: Which way is the water moving?
What kind of cell solution (outside)?
What is going to happen to the cells? A. B. C.
12% Salt
9% Salt
28% Salt
18% Salt
2% Salt
3% Salt

29. Scenario 1
Your garden is infested with slugs so you go around pouring salt on them
What type of solution is this salt?
What is going to happen to the cells of the slug? (don’t do this to the poor slugs )

30. Scenario 2
A patient is given an IV, which contains the perfect balance of glucose
What type of solution is in the IV?
What is going to happen to the cells of the human?

31. A salt water fish is put into a freshwater aquarium.
Scenario 3
A salt water fish is put into a freshwater aquarium.
What type of solution is the freshwater?
What is going to happen to the cells of the fish?

32. Practice
By yourself or with a partner (anyone), work on the diffusion problems.
First try to do this by yourself, then verify your answers with a partner. Try to help each other. If you are confused, raise your hand and I will come help you!!
If you finish early, please pick up a copy of your homework. THIS WILL BE GRADED.

33. Do Now What is passive transport? What is an isotonic solution?
What is a hypertonic solution?
What is a hypotonic solution?

34. Objectives
To compare and contrast active transport vs. passive transport
To explain the process of endocytosis and exocytosis
To determine the difference between pinocytosis and phagocytosis.

35. Active Transport
when molecules move from a low concentration to a high concentration and must use ENERGY.
Example- Sodium Potassium Pump

36. Vesicular Transport
Sometimes things enter and exit the cell by forming vesicles. For example…
Endocytosis: When cells absorb molecules by engulfing them. (like pacman)

37. Endocytosis
Pinocytosis: when the substance being engulfed is a LIQUID.
Phagocytosis: when the substance being engulfed is a SOLID.

38. Vesicular Transport
Exocytosis: When cells expel unwanted materials from vesicles.

39. Vesicular Transport