1. Cell Membrane HOMEOSTASIS: internal “steady state” maintained
by the body
1. What is the cell membrane made of?
Phospholipid bilayer
Hydrophobic tails
Hydrophilic head
Phosphate head
Fatty acid tails

2. II. Cell Membrane Homeostasis Selectively Permeable
Steady state maintained by the body
Selectively Permeable
Regulates what can come in and out of the cell

3. 1. Selectively Permeable
CAN EASILY PASS:
Small, Nonpolar O2
CO2
Water (only through protein channels)
CANNOT EASILY PASS:
Large (glucose)
Polar ( exception is water because its so small)
Ion (charged)
Breathing
Good breath in 02 we want it to get to all of our cells- done, Co2 to leave easily!!!!
Demo 6.3 online activity

4. III. Proteins in the Cell Membrane
“Fluid Mosaic Model”
Many proteins will help the membrane
Proteins drift freely

5. Membrane Proteins Embedded
Transport Proteins
Cell Recognition Proteins- sugars hang off proteins
Receptors Proteins- receive signals
Enzymes- proteins that make reactions happen
Dopamine-

6. Cell Recognition Proteins
Sugars hang off of proteins in the cell membrane
Give us different blood types
Vary between species, between types of cells, and even individuals
Blood transfusion – red blood cells have different glycoproteins on them
Example Xenotransplantation-
An antigen is any substance that causes your immune system to produce antibodies
Is the universal donor- no antigen on it no other blood type reactions ( can only accept O)
AB blood can accept A blood, B blood, O blood

7. Receptor Protein
Receptor Protein- is a cell membrane protein that receives a signal
Finish with period 5- tomorrow they have lab

8. Transport
Passive trasnport- no energy
Active trasnport – energy

9. 1. Passive Transport: Diffusion
The movement of particles HIGH concentration to LOW concentration
Why?
Molecules are always in random motion
Ex.
Perfume
Food coloring
Tea bag
On cold days must wear more molecule move slower- faster in the heat

11. b) Equilibrium- particles equally spread out

12. 2. Passive Transport: Osmosis
Diffusion of water from HIGH to LOW concentration
Solute: Substance in solution that is dissolved (ex. Sugar or Salt)
Solvent: Substance in solution that does the
dissolving ( ex. Water)

13. Hypotonic Environment Hypertonic Environment Isotonic Environment
TONICITY
Hypotonic Environment
Hypertonic Environment
Isotonic
Environment
Don’t draw- have students fill out charts – print 4 pages

14. Isotonic Same “dynamic equilibrium” “homeostasis
Diagram
Where is the most water?
Which way does water go?
Result?
Big words
Examples
97% H20
97% H2O
97% H2O
Same
Inside and outside
Even, same concentration overall
Gatorade website
“dynamic equilibrium” “homeostasis
contact lens solution, Gatorade

15. Hypotonic Outside Inside Burst, get bigger; firm
Diagram
Where is the most water?
Which way does water go?
Result?
Big words
Examples
92 % H20
97% H2O
Outside
Inside
Burst, get bigger; firm
“cytolysis”- to burst; “turgid”- get firm; “turgor pressure” :pressure inside plant cells to help stand upright
- Distilled water ( 100% Water)
- Plants standing upright

16. There is a 20 second video of contractile vacuole attached to image
There is also a short video of RBCs in pure water attached to image

17. Hypertonic Candy, sugar, salt on bushes/grass, gargle with salt water
Diagram
Where is the most water?
Which way does water go?
Result?
Big words
Examples
97% H20
80% Water
Inside
Outside
Smaller, shrink, go limp
HONORS CRENATION- means red blood cells shrink!
“plasmolysis”- to wilt, shrivel, loss of pressure; “flaccid”- go limp
Candy, sugar, salt on bushes/grass, gargle with salt water

18. Hypertonic Red Blood Cells
Short 40 second video of RBCs shrinking in salt solution attached to picture
WHY DOES SODA MAKE YOU MORE THIRSTY
salt a slug!!!!!

19. Check Yourself
Is the lettuce in a hypertonic isotonic hypotonic environment and why??
Poll
6.3 online activity!! Page 1 and 2

20. Passive Transport: 3. Facilitated Diffusion
diffusion across a membrane through transport proteins
Ex. sugars, ions ,
alcohol
b) NO ENERGY: From HIGH to LOW concentration

21. V. Active Transport
Movement of molecules across a membrane require energy
From LOW to HIGH concentrations!
a) Why?
To maintain a certain internal environment
To transport large molecules in/out
Remove salt from our cells

22. The water from soil moves into roots from HIGH to LOW
The water from soil moves into roots from HIGH to LOW. But then eventually, the roots will have more water. To prevent the water from going back out, the tree uses ACTIVE TRANSPORT to keep pumping more water in.
H2O
H2O
H2O
H2O
H2O
H2O

23. Active Transport C) Some Types of Active Transport 1. Exocytosis
Removal of materials
Vesicle fuses with membrane, forcing contents out

24. Active Transport 2. Endocytosis
process of taking in materials by infolding of the cell membrane, forming a vesicle
Ex.
Phagocytosis: Large particle/food
Amoeba
Amobea eats paramecium

25. 6.3 animation- cell eat yeast

26. Active transport video- cystic fibrous

27. VI. Concentration Gradient
measurement of how the concentration of
something changes from one place to another
Passive Transport:
molecules go DOWN concentration gradient
from HIGH to LOW concentration
Active Transport:
molecule go UP concentration gradient from
LOW to HIGH concentration
If I get to it

28. Example of DOWN concentration gradient:
Students going from classrooms into hallways for next class
Example of UP concentration gradient:
At a concert, moving into the crowd towards crowded stage

29. Review Video of Transport
Why does a plant like hypotonic but an animal does not?

30. Elodea Plasmolysis

32. “Egg”citing “Eggs”periment Cell membrane

33. Egg Lab: Osmosis