1. Cell Transport

2. Maintaining Balance
Homeostasis – process of maintaining the cell’s internal environment
Cannot tolerate great change
Boundary between cell and the environment
What provides this?

3. Plasma Membrane Hydrophobic; Fatty Acid Tail Polar Head; Hydrophilic
Fluid Mosaic Model
Selective Permeability
Phospholipid bilayer
Hydrophobic; Fatty Acid Tail
Polar Head; Hydrophilic

5. Cholesterol
Provides stability
Transport Proteins
Carbohydrates
Other Proteins
Cell recognition (immune system)

8. Recall Following Terms
Solution
Diffusion
Concentration gradient
Results in uniform concentration

9. Osmosis Cells try to reach equilibrium
Diffusion of water across a selectively permeable membrane; 3 results
Isotonic
Hypertonic Tonicity
Hypotonic

12. Isotonic Solute concentration of solution equal to that of cell
No net water movement

15. Hypertonic Solute concentration of solution higher than cell
More dissolved particles outside of cell than inside of cell
Hyper = more (think hyperactive); Tonic = dissolved particles
Water moves out of cell into solution
Cell shrinks

18. Hypotonic Solute concentration of solution lower than cell
Less dissolved particles outside of cell
Hypo = less, under (think hypodermic, hypothermia); Tonic = dissolved particles
Water moves into cell from solution
Cell expands (and may burst)

22. Active vs. Passive Active vs. Passive Transport
Passive requires no energy from the cell
Active requires cells to use energy, usually ATP

23. Passive Transport Have to move with the concentration gradient
Diffusion
Osmosis
Facilitated Diffusion- involves use of transport proteins but still follow rule of diffusion

25. Active Transport Movement of materials against concentration gradient
Transport proteins
Endocytosis – cell takes in material
Exocytosis – expulsion or secretion of materials from cell

28. Pinocytosis Phagocytosis