1. Osmosis and Diffusion
Chapter 7 Section 3

2. Chapter 7 Section 3

3. Cell Membrane
The cell membrane regulates what enters and leaves the cell to maintain homeostasis
also provides protection and support
Composition: double-layered sheet (lipid bilayer)
Flexible

4. Cell Membrane Semi-permeable
May contain protein molecules that are embedded in the lipid bilayer which form channels and pumps to move larger material across the cell membrane
Carbohydrate molecules are attached to many of these proteins (“the claw”) and act as chemical identification cards

6. Passive Transport Diffusion “Down a Slide” Move from high to low
More concentrated to less concentrated until reaches equilibrium in the absence of other influences
Does NOT require energy

7. Passive Transport Simple Diffusion diffusion across a membrane
Facilitated Diffusion
Diffusion of particle that are too large
to pass through membrane are assisted
by proteins to get from one side to
another
(channel or carrier proteins)

8. Diffusion of Particles

10. Osmosis
Diffusion of water across a selectively permeable membrane
No energy required because moving from an area of high concentration to low concentration
Salt Sucks

11. Hypotonic Solutions “HIPPO”
Solute concentration OUTSIDE cell is LOWER (below strength) than INSIDE the cell (meaning that MORE salt is INSIDE the cell)
Remember SALT SUCKS!!!!
Water moves INTO the cell causing it to SWELL
Cytolysis – animal cells bursting because too
much water

12. Hypotonic Solutions “HIPPO”

13. Hypertonic Solutions “HYPER”
Solute concentration OUTSIDE cell is HIGHER (above strength) than INSIDE the cell (meaning that MORE salt is OUTSIDE the cell)
Remember SALT SUCKS!!!!
Water moves OUT of the cell causing it to
SHRIVEL

14. Hypertonic Solutions “HYPER”

15. Isotonic Solutions “I SO HAPPY”
EQUAL solute concentrations inside and outside of cell
water diffuses in and out of cell at equal rates so cell stays the same

16. Isotonic Solutions “I SO HAPPY”

17. The Effects of Osmosis on Cells

18. Involves moving molecules “uphill” against the concentration gradient
Active Transport
Involves moving molecules “uphill” against the concentration gradient
Going up the slide
Requires energy
May cause protein channel to
Change shape

19. Active Transport

20. Active Transport continued…(Endocytosis)
“pac-man”
Cell membrane encloses particle forms a pouch (vesicle) and pinches off into cell
Pinocytosis (solutes/fluids)
Phagocytosis (large solid particles)

21. Active Transport continued….(Endocytosis)

22. Active Transport continued….(Exocytosis)
Pushing substances out of the cell, such as the removal of waste
Think of a zit and popping it

23. Active Transport continued….(Exocytosis)

24. Describe the specialization of cells in your own words.

25. Cell Specialization Chapter 7 Section 4
Cells develop in different ways to perform different tasks
Just like doctors specialize in a certain field of study

26. 4 levels of organization
1. individual cells
2. tissues – group of similar cells working together to perform a particular function
Muscle
Epithelial
Nervous
Connective

27. 4 levels of organization
3. organs – group of tissues working together to perform a specific function
4. organ systems – group of organs working together to perform a specific function