4 II.) Passive Transport Diffusion Definition: The movement of particles from areas of high concentration to low concentration
5 EquilibriumContinuous movement of particles, but no change in concentrationWhen is equilibrium reached when discussing cell membrane transport?When the concentrations of particles are the same on both sides
6 Facilitated Diffusion Particles flow from high concentration to low concentration but this time they need the help of proteins to get through the cell membrane.
7 Passive transport (cont.) OsmosisThe diffusion of water across a selectively permeable membraneImportant in maintaining cell homeostasisWater flows to side of membrane where the water concentration is lower until equilibrium is reached
8 Osmosis (cont.)Osmosis is controlled by the amount of solutes on either side of a membrane
9 Remember, this is important, Osmosis deals with what? The movement of particlesThe movement of glucoseThe movement of waterThe movement of lipids123456789101112131415161718192021222324252627282930
10 Osmosis – Types of Solutions When dealing with osmosis, water can either move into the cell or out of it.We describe the solutions that cells are in as either hypotonic, isotonic, or hypertonic.90%What are the concentrations?40%
11 Isotonic SolutionIsotonic solution – Concentration of solute is the same in the cell and the area around the cell.
13 Hypotonic SolutionHypotonic Solution – Concentration of solute is lower in the solution than in the cell.Where is water going to move in order to reach equilibrium (Equal concentrations)?Inside the cell
14 Hypotonic solutionsSince water moves into the cell the cell can explodeSo, Hypotonic solution, low concentration of solute, cell can explode
16 Hypertonic SolutionHypertonic solution – concentration of solute is higher in the solution than in the cell.Where is water going to move in order to reach equilibrium (Equal concentrations)?Outside the cell
17 Hypertonic solutionsSince water moves out of the cell the cell will shrinkSo, Hypertonic solution, high concentration of solute, cell will shrink