Passive Transport

1. Passive Transport Diffusion Osmosis Facilitated Diffusion

2. Diffusion Lab - Materials

3. Diffusion Lab - Procedure

4. Passive Transport Main Idea Three Types Diffusion Osmosis Facilitated Diffusion • Does NOT use the cell’s energy to move materials in and out of the cell

5. Diffusion • Remove the Lid • Passive Transport: Diffusion • How Diffusion Works

6. Diffusion • The net movement of substances from areas of high concentration to areas of low concentration • A concentration gradient is the difference in concentration between two areas

7. Diffusion

8. Diffusion • When a substance has evenly dispersed, it has reached equilibrium • In equilibrium, there is no longer a concentration gradient

9. Diffusion Across Membranes PERMEABLE MEMBRANES SEMI-PERMEABLE MEMBRANES Diffusion only occurs with someparticles if there is a concentration gradient Particles diffuse until equilibrium is reached • Diffusion occurs if there is a concentration gradient from one side of the membrane to the other • Particles diffuse until equilibrium is reached

10. Diffusion Across Membranes DEPENDS ON… EXAMPLES Cell Wall Cell Membrane Window/Door Screen Coffee/Tea Filter Contact Lenses • Particle Size • Saturation (concentration gradient) • Particle Charge

11. Diffusion Lab - Materials

12. Diffusion Lab - Procedure

13. Diffusion Lab – Cell Model • Cell Membrane – Plastic Bag • Cytoplasm – Cornstarch • Water-Iodine Solution – Cell’s Environment

14. Diffusion Lab - Observations

15. Diffusion Lab - Analysis • The cell membrane is semi-permeable because it only allowed certain particles to pass through • Iodine diffused into the cell • Cornstarch did not diffuse out of the cell