Cellular Transport

1. Cellular Transport Unit 5

2. Passive Transport • Does not use energy 1. Diffusion • Movement of particles from an area of higher concentration to an area of lower concentration. • Dynamic Equilibrium - Tries to reach an equal concentration inside and outside the membrane 2. Osmosis – Diffusion of Water

3. 3. Facilitated Diffusion • Passive transport of materials across the plasma membrane with the aid of transport proteins. • Move from high to low concentration • Transport proteins provide openings for particles to pass through • Move molecules that may not be soluble in lipids or may be too large to pass through the pores in the cell membrane.

4. Three Types of Solutions • 1. Isotonic – concentrations are the same inside the cell as they are outside the cell

5. Three Types of Solution Cont. • 2. Hypotonic – concentration of substances is lower outside the cell than the concentration of substances inside the cell.

6. Hypotonic cont. • The cell swells and may burst in animal cells • Swelling will cause a gain in mass • As a plant cell swells, the cell wall supports the cell so it won’t burst, but it will become more firm.

7. Three Types of Solution Cont. • 3. Hypertonic – the concentration of substances outside the cell is higher than the concentration of substances inside the cell.

8. Hypertonic cont. • Animal cells shrivel • Plant cells lose water mainly from the central vacuole. The cell membrane and cytoplasm shrink away form the cell wall. This causes plants to wilt.

9. Active Transport • Requires energy from the cell • Moves from low to high concentration • Ions move in this manner.