1. Cellular Transport Yeast cells stained with fluorescent dye
The cell membrane

2. The Cell Membrane Selectively permeable (semi-permeable)
allows only certain substances to pass through
cannot control the movement of water
Cell membrane

3. The fluid mosaic model
double layer of lipids with proteins scattered throughout
flexible, phospholipids move with in the membrane

4. Parts of the cell membrane
Phospholipids
lipids with a phosphate group attached to one end
makes molecule polar so it can react with water

5. Parts of the Cell Membrane
Transport Proteins- allows needed substances or waste materials through membrane

6. Parts of the Cell Membrane
Cholesterol
stabilizes the phospholipids
does not allow fatty acid chains to stick together
cholesterol

7. Type of Cell Transport Simple diffusion Osmosis Facilitated diffusion
Active transport
Endocytosis/Exocytosis

8. Diffusion
Particles move from an area of high concentration to an area of low concentration
Moves “down” or “with” the concentration gradient
Does not require energy

9. Diffusion Factors effecting the rate of diffusion
1. temperature (as temp increases rate increases)
  2. pressure (as pressure increases rate increases)
  3. steepness of the concentration gradient (the steeper the gradient the faster the diffusion)

10. Osmosis Movement of WATER across a cell membrane Cell has no control
continues to move until [inside] = [outside] called dynamic equilibrium
[ ]- means “the concentration of”

11. Types of Solutions
Isotonic
Hypotonic
Hypertonic

12. Types of Solutions Isotonic – [water inside] = [water outside]
Hypotonic – [water inside] < [water outside]
solutes are higher inside the cell
water flows in, cell swells
cell could burst if continues
Hypertonic – [water inside] > [water outside]
solutes are higher outside the cell
water leaves cell, cell shrinks

13. Types of Solutions Isotonic Hypotonic Hypertonic Water particle
Solute particle

14. Types of Solutions Water always moves toward the solution with
the highest concentration
of solute

15. Type of Solutions
Notice water level rises on side of membrane with the highest solute concentration

16. Types of Solutions Effects on Animal Cells
The pictures below are red blood cells in different concentrations of salt solution. Identify which pictures are hypotonic, isotonic, and hypertonic solutions.
Isotonic Hypertonic Hypotonic

17. Types of Solutions Effects on Plant Cells
Which of these cells are in a hypotonic solution? Hypertonic solution?
Hypotonic Hypertonic

18. Facilitated Diffusion
moves down the concentration gradient with aid of protein
Does not use energy
most glucose moved this way

19. Passive Transport NO energy required
Diffusion, Osmosis, and Facilitated Diffusion are all forms of passive transport

20. Active Transport Requires energy
moves from an area of low concentration to an area of high concentration
moves “up” or “against” the concentration gradient
glucose moved from blood stream into liver for storage

21. Active Transport

22. Moving large particles across the cell membrane
Endocytosis – movement of large particles into the cell
Exocytosis – movement of large particles out of the cell
Endocytosis
Exocytosis