effects of osmosis on plant tissue

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

  How to investigate osmosis on plant tissue
• What is osmosis?

  Diffusion of water through a membrane
• What happens to plant cells in water?

  They expand as water enters
• What occurs when plant cells are placed in a concentrated solution?

  Water moves out, causing shrinkage
• What vegetable is commonly used to investigate osmosis?

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

  The skin can affect osmosis
• What tool is used to produce potato cylinders?

  Cork board
• What length should the potato cylinders be trimmed to?

  About three centimeters
• What is the first step after preparing the potato cylinders?

  Measure their length and mass
• Why do we use distilled water instead of tap water?

  Distilled water has no dissolved substances
• How long should the potato cylinders be left in the solutions?

  Overnight
• What should be done after removing the potato cylinders?

  Gently roll them on paper towel
• What is the equation for calculating percentage change?

  Percentage change = (change/original) × 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 show?

  Mass gain in water, loss in sugar solution
• What does the concentration at the x-axis crossing represent?

  Approximate concentration inside the cell
• What does the x-axis crossing point on the graph indicate?

  No change in mass occurs
• Where can you find more questions on this practical?

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

  1. Peel the potato.
  2. Use a cork board to create cylinders.
  3. Trim cylinders to the same length.
  4. Measure length and mass of cylinders.
  5. Place cylinders in different sugar solutions.
  6. Leave overnight for osmosis to occur.
  7. Remove and roll on paper towel.
  8. Measure length and mass again.
  9. Calculate percentage change.
• What are the key factors affecting osmosis in this experiment?

  • Concentration of sugar solution
  • Surface area of potato cylinders
  • Duration of immersion
  • Temperature of the environment