Osmosis

• What is osmosis

  The movement of water from a dilute to a more concentrated solution through a partially permeable membrane
• What is a partially permeable membrane

  A membrane that only allows some particles through
• Define isotonic

  When the concentration of solute in a solution outside the cell is the same as the internal concentration
• Define hypertonic

  When the concentration off solute in a solution is higher that the internal concentration
• Define hypotonic

  When the concentration in a solute in a solution outside the cell is lower than the internal concentration
• Why isosmosis so important in plants

  Water moves in thorugh osmosis causing the vacuole to swell and press against the cell wall resulting in pressure so no more water can enter the cell (turgor)

  This makes cells hard and rigid which keeps stems and leaves rigid
• What happens if the solution surrounding the cell is hypertonic to the cell contents

  Water will leave the cell by osmosis so the cell will no longer be hard and swollen meaning it becomes flacid as there's no pressure on the cell wall so the plant will wilt
• What happens if more water is lost by osmosis

  The vacuole and cytoplasm shrinks and the membrane will pull away from the cell wall . Called plasmolysis