1. Question of the Day 12-7 Homeostasis = ???
What kind of solution can cause a cell to burst (explode)? isotonic, hypotonic, or hypertonic?
Water crosses through a ________ ____________ __________ during osmosis.

2. Review

3. 12-7
Lab
Pages 6 and 7 questions

4. 12-8
Question of the Day
Get out a clean piece of paper you can turn in
Questions:
What is osmosis?
What is a hypertonic solution? What happens to the cell in this type of solution?
What is a hypotonic solution? What happens to the cell in this type of solution?

5. Control = 56.5 grams

6. 12-8
Lab
Notes Page 8

7. Contractile Vacuoles –
Organelle that excretes excess water from cells
Uses ATP
Usually found in unicellular freshwater organisms.
This prevents them from bursting in a hypotonic solution. 7

8. Contractile vacuole 8

9. Plasmolysis –
loss of turgor pressure in plant cell due to loss of water
What happens to a plant during plasmolysis?
The plant wilts
The plants plasma membrane and cytoplasm will shrink away from the cell wall 9

10. REVIEW: What will happen to an Elodea Leaf in a hypertonic solution?
Water will leave the cell…
…which is called playsmolsis, which will cause the plant leaves to wilt
Cell membrane
Cell membrane

11. Review If we put Elodea leaves in a hypotonic solution, what happens?
Water will move into the cell….
….which will cause the cell to swell. If it’s an animal cell it will….
…burst, UNLESS the cell has a
Contractile vacuole to pump the water out. to
Cell membrane pushing
against the cell wall

12. Summary of Hypo/Hypertonic solution changes on a RBC.12

13. Review If the cell shrinks, it is in what type of solution?
If the cell is at equilibrium with it’s environment, its in what type of solution?
If the cell swells, it’s in what type of solution?
Water –90%
Salt – 10%
Water 95%
Salt 5%
Water 64%
Salt 36%
Water 44%
Salt 56%
Water 50%
Salt 50%
Water 50%
Salt 50% 13

14. pages 6-7 assignment

15. Egg Lab Report Graph Add a column to you data table: Must be colored
Starting Mass (grams)
Final Mass (g)
Change in mass (g)
% Change in Mass
((Initial Mass – Final Mass) / Initial Mass) x 100
Egg in shell
=====
====
===
Vinegar
Corn Syrup
Distilled
Graph
Must be colored
Graph your starting mass and then use your final mass data which is in blue
Add a column to you data table:
“Percent Change in Mass”
((Initial Mass – Final Mass) / Initial Mass) x 100
Calculate all the changes in mass for your egg

16. Egg Lab Report Analysis of your Data: What you should turn in:
Be sure you are using the terms we’ve discussed in class in your explanation of your results.
Example
What you should turn in:
Page 1 – Directions
Page 2 – Written lab report
Page 3 – Graph
Page 4 – Your actual lab procedure

18. Selective Permeability –
plasma membrane to allows some materials to pass while keeping others out
Why is selective permeability important?
So the cell can allow important substance in (water, oxygen, glucose) and keep harmful substances out (bacteria).

19. Passive Transport This process uses no ATP Passive Transport –
movement of particles across membranes by diffusion
This process uses no ATP
Molecules moving from hi concentration  low concentration

20. Facilitated Diffusion –
name for passive transport using transport proteins
Does not use energy!!!
Example:
Glucose going from high concentration outside cell low concentration inside the cell
Why doesn’t this need energy?
Because it’s still along the concentration gradient
transport proteins

24. Transport / carrier proteins –
proteins that assist facilitated diffusion

25. Ion channels are ion specific
proteins transport ions from high concentration to lower concentration
Ions like Na+, Ca+, etc are not soluble in lipids, so they must travel through proteins channels
Ion channels are ion specific
Some channels are always open, some have gate
Gates open from stimuli: stretching of cell membrane electrical or chemical signals

27. Active Transport Active Transport – ATP (adenosine tri-phosphate) –
transport of materials against a concentration gradient – requires energy
ATP (adenosine tri-phosphate) –
the ENERGY molecule for the cell
Breaks down from ATP  ADP (Adenosine di-phosphate)
Hydrolysis of the phosphate releases energy

28. Active Transport Example http://www. youtube. com/watch

29. Sodium-potassium Pump – transfer protein example
Transfers Na+ out and K+ in
Creates electrical gradient which is important for nerve impulses

31. Na+ / K+ Pump

32. Endocytosis –
when a cell surrounds and takes in material from the environment
Uses ATP

34. Endocytosis

35. Pinocytosis –
Transport of fluids into the cell

36. Phagocytosis – Phagocytes –
Transfer of large particles / cells into the cell
Phagocytes –
Cells that ingest bacteria / viruses and lysosomes fuse w/ vesicle to destroy them before harm done

37. Exocytosis –
when a cell expels materials to the extracellular environment
Cell exports proteins, hormones and wastes this way
This process uses ___ATP___

38. Endo / Exocytosis

39. Exocytosis and endocytosis

40. The End

41. Warm Up 1-5
Draw and Label Each – hypotonic, hypertonic, isotonic, active transport, diffusion: (Blue circles = cells)
NaCl 12%
NaCl 25%
NaCl 20%
NaCl 35%
Sugar 10%
Sugar 5%
ATP used

42. Dialysis Tubing Lab Groups of two or three (NOT 4)
Read through part 1 – create a flow chart of the procedure

43. Warm Up 1-6 How is the dialysis tubing “selective”?
Get out your dialysis tubing lab.

44. Warm Up 1-6 Get you Part II lab set up
Make your observations – finish lab questions
Turn in your lab.
Today:
Begin photosynthesis chapter

45. Warm Up 1-7 Get your Part II lab set up Make your observations
Finish the lab questions – Turn in Lab
Today:
Start Photosynthesis!!

46. Hypo / Hypertonic Solutions