BIO1042 Lecture Notes - Lecture 16: Euryhaline, Stenohaline, Semipermeable Membrane
14 Sep 2018
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Document Summary
Living organisms are an aqueous solution within a membrane. Is the movement of molecules through a permeable membrane spreads molecules out evenly into the available space is movement down a concentration gradient. Osmosis is the movement of water across a semi-permeable membrane. Solute molecules are too big to cross membrane, so the solvent molecules (water) move to reach an equilibrium: where both concentrations are equal. Water balance of cells without walls: tonicity is the ability of a solution to cause a cell to gain or lose water, has a great impact on cells without walls. For a cell to become the same concentration as surrounding solution, will it need to lose or gain water: plant cells have cell walls, animal cell only have cell membranes. If a solution is isotonic iso = same, tone = tension the concentration of solutes is the same as it is inside the cell there will be no net movement of water.
