effects of osmosis on plant tissue

• What should you be able to describe by the end of the video?

  How to investigate the effect of osmosis on plant tissue
• What is osmosis?

  The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• What happens to a plant cell when it is placed in water?

  Water moves into the cell by osmosis, causing the cell to expand
• What occurs when a plant cell is placed in a concentrated solution?

  Water moves out of the plant cell by osmosis, causing the cell to shrink
• What type of vegetable is commonly used to investigate osmosis?

  Potato
• Why do we peel the potato before the experiment?

  Because the potato skin can affect osmosis
• How do we ensure all potato cylinders are the same diameter?

  By using a cork borer
• What is the recommended length for the potato cylinders?

  Approximately three centimeters
• Why is it important to measure the length and mass of each potato cylinder before the experiment?

  To determine the effect of osmosis later
• How much of a 0.5 molar sugar solution is added to the first test tube?

  10 centimeters cubed
• Why do we use distilled water instead of tap water in the experiment?

  Because distilled water contains no dissolved substances that could affect osmosis
• What should be done to the potato cylinders after leaving them overnight?

  Gently roll them on paper towel to remove surface moisture
• Why is it important not to press on the potato cylinders when removing surface moisture?

  To avoid forcing water out of the cells
• What is the formula to calculate percentage change?

  Percentage change = (change in value / original value) × 100
• If a potato cylinder has a starting mass of 1.56 grams and increases by 0.25 grams, what is the percentage change?

  +16.03%
• If a potato cylinder has a starting mass of 1.32 grams and decreases by 0.19 grams, what is the percentage change?

  • 14.39%
• What does the graph of percentage changes in mass or length against the concentration of the sugar solution show?

  In water, the potato cylinder gains mass, while in concentrated sugar solution, it loses mass
• What does it mean when the graph crosses the x-axis?

  There is no change in mass, indicating equal concentration inside and outside the cell
• Where can students find more questions on this required practical?

  In the vision workbook
• What are the steps to investigate the effect of osmosis on plant tissue?

  1. Peel the potato to remove the skin.
  2. Use a cork borer to create three cylinders of potato.
  3. Trim the cylinders to the same length (around 3 cm).
  4. Measure the length and mass of each cylinder.
  5. Place each cylinder in a test tube with different sugar solutions.
  6. Leave the cylinders overnight.
  7. Remove and roll on paper towel to remove surface moisture.
  8. Measure the length and mass again.
  9. Calculate the percentage change in length and mass.
• What are the effects of osmosis on potato cylinders in different sugar solutions?

  • In distilled water: Potato cylinders gain mass (water moves in).
  • In concentrated sugar solution: Potato cylinders lose mass (water moves out).
  • At equilibrium: No change in mass (equal concentration inside and outside).