| A | B |
| smells spread | by diffusion |
| water spreads | by osmosis |
| concentration gradient | the difference between 2 concentrations |
| semi-permeable membrane | allows some molecules through |
| fully permeable membrane | lets everything through |
| partially permeable membrane | = semi permeable |
| impermeable membrane | lets nothing through |
| cell membranes are | semi-permeable |
| cell walls are | fully permeable |
| solute | a dissolved solid in a solution |
| solvent | the liquid which dissolves a solute |
| solution = | solute + solvent |
| potato left in water | will become heavier |
| potato left in strong sugar solution | will become lighter |
| osmosis is | the movement of water |
| osmosis and diffusion are | passive |
| active transport is | active |
| active transport requires | energy |
| movement of substances against a concentration gradient | requires energy |
| transport proteins | carry molecules across a membrane |