Cell Processes 1 GET OUT HOMEWORK Do Now: How can you smell perfume that someone sprays from across the room???? Brainstorm!! Homework: Activity sheet (TBD) Door windows DEMO! Terms Review Selectively Permeable will only allow certain things to pass through it Permeable means things can pass Selective not everything The cell membrane is selectively permeable to molecules Semi-permeable Sometimes the membrane will allow other molecules to pass, other times it will only allow water molecules to pass. Terms Review Solvent vs. Solute Kool-Aid Solvent = Solute = Iced Tea Solvent = Solute = Sugar Water Tea Water Solute and Solvent?? Hypertonic high concentration of solute When youre hyper, you have more energy!! Hypotonic low concentration of solute Isotonic same concentration of solutes (when comparing two solutions) Hypertonic solution means more solute in the solution than in the cell DIFFUSION: Movement of molecules of any substance from a high concentration to a low concentration. WHAT DOES THAT MEAN? This can happen in the open air, or through a selectively permeable membrane!! How? Molecules are always moving and bumping into each other More molecules = more collisions Collisions push the molecules away from each other slowly Molecules like their own space. If there are too many in one space then molecules will move to a place with less stuff (less molecules). DOES NOT NEED ENERGY TO MOVE! HIGH CONCENTRATION SPREAD OUT HOW DIFFUSION WORKS Molecules move in and out of the cell through the cell membrane Draw arrows to show which way the molecules will move Where do you observe this? Helium balloons Perfume/cologne Cigarette smoke Cooking pasta The movement of water through a membrane OSMOSIS DOES NOT NEED ENERGY TO MOVE! How do you dilute something?? There is way too much sugar powder in your drink after you make Kool-Aid. How do you fix this? 1. Try to remove the solute (difficult) 2. Add more solvent! (water) What are the consequences to a cell if too much water goes? INTO THE CELL OUT OF THE CELL BLOATS SHRINKS Hypotonic Isotonic Hypertonic NEEDS ENERGY to move substances across the membrane ACTIVE TRANSPORT USUALLY MOVES SUBSTANCES FROM A LOW CONCENTRATION TO A HIGH CONCENTRATION How? Transport proteins Think back to chemicals of life Proteins make up some cell parts Transport proteins allow active transport to happen! Active Transport Brain Pop Video https://www.brainpop.com/science/cellularlifeandgenetics /activetransport/ https://www.brainpop.com/science/cellularlifeandgenetics /activetransport/ DONT NEED ENERGY to move substances across the membrane PASSIVE TRANSPORT USUALLY MOVES SUBSTANCES FROM A HIGH CONCENTRATION TO A LOW CONCENTRATION Question: Which of the following statements concerning diffusion and active transport is correct? A. Both diffusion and active transport require cell energy. B. Neither diffusion nor active transport require cell energy. C. Diffusion requires cell energy while active transport does not. D. Active transport requires cell energy while diffusion does not.