Cellular Transport 7.4

I. Passive Transport A Passive Transport- The movement of particles across the plasma membrane WITHOUT USING ENERGY. 1. Goes WITH the concentration gradient (High to Low)

III. Passive Transport B. Types of Passive Transport 1. Simple diffusion 2. Facilitated Diffusion 3. Osmosis

I. Passive Transport Ammonia/Air Freshener demo C. Diffusion- The movement of particles from higher concentration to an area of lower concentration D. Facilitated Diffusion- The diffusion of particles using carrier or channel proteins.

I. Passive Transport E. Osmosis- The diffusion of water across a selectively permeable membrane. 1. Water moves to spread out solid particles. 2. Once again, the water particles and the solid particles are trying to reach equilibrium.

II. Osmosis 3. U Tube Demonstration (pg. 203) a). If there are more solid particles on one side of the membrane the water will actually move toward that side making the water level uneven. 1). it even works against gravity

II. Osmosis 4. Isotonic Solutions a) Most cells are surrounded by water. b) If a cell is in an isotonic solution the concentration of solid particles inside the cell is equal to the concentration of solid particles on the outside of the cell.

II. Osmosis c) The water particles still move back and forth, but at an equal rate.

II. Osmosis 5. Hypotonic Solutions a) If a cell is in a hypotonic solution the concentration of solid particles on the inside of the cell is higher than the concentration of solid particles in the solution. b) Water moves in toward the higher concentration of particles

II. Osmosis c) Memory Trick: Cells in a hypotonic solution swell like a hippo! d) Watering a plant causes a cell to take in water, increase turgor pressure and make the plant stand up.

II. Osmosis 6. Hypertonic Solution a) If a cell is in a hypertonic solution the concentration of solid particles is greater in the solution than in the cell. b) The water will move out c) Cells shrivel due to decrease in pressure (crenation)

II. Osmosis d) Memory trick: The water in the cell is hyper and wants to get out of the cell.

III. Active Transport A. Active Transport- The movement of particles across the plasma membrane that REQUIRES USING ENERGY. 1. Goes AGAINST the concentration gradient (Low to High) 2. Uses carrier proteins

II. Active Transport a. The carrier protein waits for a specific particle to bind with it. b. Energy is then used to change the shape of the carrier protein to allow that particle to enter the cell. c. The carrier protein then returns to its original shape

III. Transporting Large Molecules A. Endocytosis- The process of the cell membrane engulfing a large molecule and turning it into a vacuole inside the cell. B. Exocytosis- The process of expelling large wastes from the cell. a. Also used to release hormones

V. Transporting Large Molecules C. Endocytosis and Exocytosis both require energy.

Recap -What is diffusion? -What is osmosis? -How will the water particles move if a cell is in an isotonic solution? -How will the water particles move if a cell is in a hypotonic solution? -How will the water particles move if a cell is in a hypertonic solution?

Recap -What is passive transport? -What is facilitated diffusion? What are the two types of proteins used? -What is active transport? What type of protein is used? -Compare endocytosis and exocytosis.