Predicting Diffusion and Osmosis in Passive Transport

1. 6.3 Transport

2. 6.3 Transport: Predict the results What do you predict will happen if food coloring is dropped into a beaker of water? • Where are the molecules most concentrated to start? • Where are the molecules less concentrated to? • What is Diffusion? • The movement of molecules from a high concentration to a low concentration.

3. 6.3 Transport • KEY CONCEPT Materials move across membranes because of concentration differences. • What is a concentration gradient? • Molecules move down a concentration gradient. • Think of a slide. • Would energy be required?

4. How is Diffusion Important for cells or your Body? • For Cellular Transport • Medications, digestion, oxygen, carbon dioxide.

5. 6.3 Passive Transport Passive transport : • Molecules can move across the cell membrane through passive transport. • Does not require energy input from a cell. • There are three types of passive transport. • Simple diffusion • Osmosis • Facilitated diffusion

6. 6.3 Osmosis Diffusion and osmosis are types of passive transport. • Osmosis is the diffusion of water molecules across a semipermeable membrane.

7. 6.3 Osmosis Solutions Diffusion and osmosis are types of passive transport. • There are three types of solutions. • isotonic • hypertonic • hypotonic

8. Facilitated Diffusion Some molecules can only diffuse through transport proteins. • Some molecules cannot easily diffuse across the cell membrane. • Facilitated diffusion is diffusion through transport proteins.

9. Facilitated diffusion: • Diffusion of larger molecules through the protein channels in the cell membrane. • Passive transport- no energy needed. • Molecules move from ____ conc. to ____ conc. • Examples include: glucose, water, ions.

10. Active Transport: • Movement of molecules from______ conc. to ______ conc. • Requires energy (ATP) • Needs transport proteins • Examples- Na/K pump, endocytosis, exocytosis.

11. Transport of Large Molecules: • Vesicles used- • small membrane sacs; move products into, out, or within a cell. • Exocytosis- Materials leave a cell. • vesicle containing the protein fuses with the plasma membrane and spills its contents outside the cell. • Example- release of insulin • Endocytosis-Takes material into the cell. • vesicles bud inward from the plasma membrane • Examples- phagocytosis (solids)