1. Outline the functions of membranes. [2] Define phospholipid. [1]
Check In
Outline the functions of membranes. [2]
Define phospholipid. [1]
Homework
Study for your test on Friday Oct. 5

2. Check In Homework Define diffusion. [1]
Outline how your test preparation is going using supportive language.
Possible sentence frames:
It is my opinion that __ because __.
I believe __ because __.
Homework
Study for your test on Friday Oct. 5

3. Define osmosis. [1] Outline an example of osmosis.
Check In
Define osmosis. [1]
Outline an example of osmosis.
Homework
Cut out your cell membrane

4. Outline the process shown below. [2]
Check In
Outline the process shown below. [2]
Before:
After:

5. Outline the process shown below. [2]
Check In
Outline the process shown below. [2]
Markscheme:
Osmosis
Water leaves the cell
Hypertonic solution outside of the cell
Plasmolysis

6. Copyright Pearson Prentice Hall
2–4
The elements or compounds produced by a chemical reaction are known as
reactants.
enzymes.
products.
waste.
Copyright Pearson Prentice Hall

7. Copyright Pearson Prentice Hall
2–4
Chemical reactions always involve
changes in energy.
enzymes.
catalysts.
changes in the atomic number of the reactants.
Copyright Pearson Prentice Hall

8. Copyright Pearson Prentice Hall
2–4
The factor that prevents many energy-releasing reactions from occurring at relatively low temperatures is called
catalytic energy.
chemical bond energy.
enzyme energy.
activation energy.
Copyright Pearson Prentice Hall

9. Copyright Pearson Prentice Hall
2–4
Which of the following statements is true?
All proteins are enzymes.
All catalysts are enzymes.
All enzymes are catalysts.
All catalysts are proteins.
Copyright Pearson Prentice Hall

10. Copyright Pearson Prentice Hall
2–4
What happens to an enzyme after the reaction it catalyzes has taken place?
The enzyme is destroyed, and the cell must make another.
The enzyme holds on to the product until another enzyme removes it.
The enzyme is unchanged and ready to accept substrate molecules.
The enzyme changes shape so it can accept a different kind of substrate.
Copyright Pearson Prentice Hall

11. Notes – Membrane Transport

12. Passive transport
Movement of molecules across a membrane without using energy
Types:
Diffusion
Osmosis
Facilitated diffusion

13. Diffusion
Movement of molecules from high concentration to low concentration
Equilibrium = the concentration is the same on both sides of the membrane

14. Review #1
If a substance is more highly concentrated outside the cell than inside the cell and the substance can move through the cell membrane, the substance will
move by diffusion from inside the cell to outside.
remain in high concentration outside the cell.
move by diffusion from outside to inside the cell.
cause water to enter the cell by osmosis. 3

15. Review #3
Describe what is happening…

16. Review #3
Describe what is happening…

17. Review #4
Describe what is happening…

18. Review #4
Describe what is happening…

19. Osmosis
Movement of water molecules across a membrane from high water concentration to low water concentration
Fingersurvey:
Where is there a high water concentration?
To which number will water move? 1 2

20. Osmosis
Movement of water molecules across a membrane from high water concentration to low water concentration

21. Osmosis
Movement of water molecules across a membrane from high water concentration to low water concentration
Hypertonic = higher solute concentration
Hypotonic = lower solute concentration
Isotonic = equal solute concentration

22. Review… 1 2

23. Facilitated Diffusion
Glucose molecules
Facilitated Diffusion
Diffusion of molecules across a membrane through protein channels
During facilitated diffusion, molecules, such as glucose, that cannot diffuse across the cell membrane’s lipid bilayer on their own move through protein channels instead.
Protein channel

24. Review
Describe what is happening…

25. Review
Describe what is happening…

26. Concentration Gradient
A difference in concentration on either side of a membrane

27. Active transport Movement of molecules across a membrane using energy
Movement of molecules from low concentration to high concentration
Active transport is done by protein pumps
Molecule to be carried

28. Copyright Pearson Prentice Hall
Last Review
The process by which molecules diffuse across a membrane through protein channels is called
active transport.
endocytosis.
facilitated diffusion.
osmosis.
Copyright Pearson Prentice Hall

29. Check Out
Define osmosis (use the word concentration in your definition). [1]
Outline an example of osmosis. [1]
Homework
Study for your test on Friday Oct. 5

30. Define active transport. [1]
Warm up
Define active transport. [1]
Outline the relationship between active transport and concentration gradients. [2]
Homework
none

31. Warm Up What is an analogy for surface area in a cell?
What is the relationship between cell size and the surface area to volume ratio? Why is it important?

32. Warm Up
What was the smallest object from the homework last night? What is the definition?
What was the shortest inverse location?
What was the longest inverse location?