osmosis

• What is the plant tissue used in the osmosis experiment?

  Potato
• Why is it important to use potato cylinders of the same diameter?

  To compare results more easily
• What is the purpose of cutting the ends off the potato cylinders?

  To remove impermeable potato skin
• What is osmosis primarily concerned with?

  Water movement in plant cells
• What length should the potato cylinders be measured to?

  Three centimeters
• How is the length of the potato cylinders measured?

  Using a ruler
• Why is distilled water used in the experiment?

  It is pure water for comparison
• What happens to the potato cylinders after being left overnight?

  They absorb water and change mass
• How is excess water removed from the potato cylinders after the experiment?

  Using a paper towel
• What does an increase in mass indicate in the distilled water sample?

  Water entered the potato cells
• What does a negative percentage change in mass indicate?

  Mass has decreased
• What are the steps to calculate percentage change in mass?

  1. Subtract initial mass from final mass
  2. Divide by initial mass
  3. Multiply by 100
• What is the expected trend in mass as sucrose concentration increases?

  • Mass increases in distilled water
  • Mass decreases in higher sucrose concentrations
  • No change at a certain concentration
• What does the line of best fit in the graph indicate?

  • Shows the relationship between sucrose concentration and mass change
  • Indicates the concentration of sugar in potato tissue
• What factors can affect the accuracy of the osmosis experiment?

  • Inconsistent potato sizes
  • Measurement inaccuracies
  • Environmental conditions (temperature, evaporation)
• independent variable

  concentration of sugar solution
• Dependant variable

  Percentage change in mass
• Control variable

  • type o sugar
  • age and type of potato
  • time potato left in solution
  • time spent drying potato chips
• step one

  cut potatoes into identical chips that are the same length and mass - make them approximately 3cm in length. Record initial measurements on a table
• step two

  measure 10 cm cubed of each concentration of sugar or salt solution and put into clearly labelled boiling tubes. measure the same volume of distilled water in the fifth tube and label this - it will be the control
• step three

  add one potato cylinder to each tube and leave them there for a fixed amount of time before removing them and blotting them dry with paper towels. Then measure new mass and length of each potato cylinder and record this for each concentration. Calculate change then percentage change.