1. Moving materials in and out of the cell.
Cell Transport
Moving materials in and out of the cell.

3. Cell Membrane “Fluid Mosaic Model”
Phospholipid Bilayer- phosphate head, lipid tail
Semi-permeable – allows some materials through, but not all (hydrophobic- hates water, hydrophilic- interacts with water)

4. Cell Membrane Continued
Carrier proteins - transport material in and out of the cell
Channel Proteins – allow material to flow in and out
Recognition Proteins – help cell identify their surroundings
Cholesterol- helps the fatty acids tails to not stick together

5. Passive Transport
Passive Transport- requires no energy

6. Passive Transport Types
Simple Diffusion- molecules move from an area of higher concentration to lower concentration
occurs until equilibrium is reached
Ex. cologne

7. Passive Transport Types
Osmosis- diffusion of water molecules thru a selectively permeable membrane
the force exerted by osmosis is called osmotic pressure

8. Cell in Solution
Hypotonic solution -less dissolved material in the solution than the cell, causing (water flows into the cell) (increases osmotic pressure, cells may burst).
hypotonic

9. Cell in Solution
Hypertonic solution – more dissolved material in solution than in the cell (water flows out of the cell)
hypertonic

10. Isotonic
Isotonic- same amount of dissolved material in the solution and cell
Isotonic

11. Why cells do not Burst
cells in organisms don’t come into direct contact w/ water
plant cells have cell walls that keep the cell from expanding
some cells use pumps

12. Passive Transport Types
Facilitated diffusion - diffusion with the assistance of a channel protein.

13. Active Transport Active transport - requires energy
Carrier protein moves material from low to high concentration (usually pumps)

14. Moving large objects
Endocytosis – a vesicle formed to take materials into the cell
Exocytosis – a vesicle putting materials out of the cell