Diffusion and Osmosis Cell membrane selectivelysemi permeable which
Diffusion and Osmosis
�Cell membrane- selectively/semi permeable, which means that some substances can pass through the membrane while others cannot. ◦ Think of the analogy- The cell membrane is like a window screen, certain things can pass in and out of the screen (dust, pollen, rain, etc. ) while other things are kept out (flies, bees, leaves, etc. ).
�The cell membrane- allows certain things to come into and out of the cell such as…. ◦ IN �Oxygen, food, water OUT � Waste, Carbon Dioxide All of these substances must pass through the cell membrane.
�This movement is called DIFFUSION! ◦ Diffusion is the process by which molecules move from an area of high concentration to an area of low concentration. The molecules spread out to fill the space. They don’t have to move through a cell membrane.
�What causes this to happen? ◦ Molecules are always moving. If there a lot of molecules in one area (high concentration) and they are all moving they will bump into one another and spread out (to low concentration) over time. ◦ *Demonstration air freshener
Diffusion in Daily Life vperfume vodor vthe or deodorant of food cooking smell of a burning incense va person smoking va tea bag in a hot cup of water
�Osmosis is the diffusion of water molecules through the cell membrane. (#13 on outcomes) �Water will move from an area of higher concentration to an area of lower concentration as in diffusion. . Gummy Bear Osmosis
Osmosis in Daily Life vkidney vrice dialysis or beans are soaked in water vroots of plants vpreserving fruits and vegetables vdehydrate of produce meat
- Slides: 8