Osmosis

• What is osmosis?

  The movement of water from a less concentrated solution to a more concentrated one through a partially permeable membrane.
• Why does water move from a dilute solution to a concentrated solution during osmosis?

  Because it moves from an area of high water potential to low water potential, down the concentration gradient.
• What type of transport is osmosis classified as?

  Passive transport.
• What happens to a cell placed in a dilute solution?

  Water will move into the cell.
• What are the three types of solutions in relation to osmosis?

  • Isotonic: No movement of water; concentrations are equal.
  • Hypertonic: Water moves out of the cell; external solution has a higher concentration.
  • Hypotonic: Water moves into the cell; external solution has a lower concentration.
• What occurs to animal cells in a more dilute external solution?

  They may burst due to excess water intake.
• What happens to animal cells in a more concentrated external solution?

  Excess water leaves the cell, causing it to shrivel.
• What is turgor pressure in plant cells?

  Pressure from water moving into the vacuole, keeping the plant rigid.
• What is plasmolysis in plant cells?


  When the cell membrane moves away from the cell wall due to water loss.
• How can the effect of sugar solutions on plant tissue be investigated?

  • Place potato tubers in different concentrations of sugar solution.
  • Measure mass before and after to determine water movement.
  • Calculate percentage change in mass and plot results.