1. Movement Through the Cell Membrane

2. Cell Membrane
The thin flexible barrier around the cell that regulates what enters and leaves.
Selectively permeable- some substances can pass and others cannot

3. Cell membrane is made up of:
Carbohydrates- act as chemical identification cards (NAME TAGS) for cells to identify one another. (Security)
Lipid bilayer- two layers of fat (Fence)
Protein channels- that move materials across. (Gates)
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5. Diffusion (Passive Transport)
The movement of molecules from an area of high concentration to an area of low concentration.
Does not require energy!
Equilibrium (Think equal)-When concentration of molecules inside/outside cell is about equal.
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6. Facilitated Diffusion (Passive Transport)
When molecules are too large to pass through membrane lipids
carrier proteins (protein channels) help move molecules from high to low concentration
No cell energy used.

7. Diffusion Animation

8. Osmosis (passive transport)
Diffusion of water across a selectively permeable membrane.
Does not require energy
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9. Osmosis Animation

10. Active Transport (uses cell energy)
Endocytosis-(think enter) -when cells ingest materials too big to pass through the membrane (macromolecules, large particles, other cells).
EX: phagocytosis

11. Active Transport (cont.)
Exocytosis-(think exit)- substances removed from cell by vesicles
Remove: proteins, toxins, waste products

12. Active Transports

13. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
Hypotonic: The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute; High water)
Result: Water moves from the solution to inside the cell): Cell Swells and bursts open (cytolysis)!

14. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
Hypertonic Solution
Hypertonic: The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute; Low water)
shrinks
Result: Water moves from inside the cell into the solution: Cell shrinks (Plasmolysis)!

15. Osmosis Animations for isotonic, hypertonic, and hypotonic solutions
Isotonic Solution
Isotonic: The concentration of solutes in the solution is equal to the concentration of solutes inside the cell.
Result: Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium)