required practical

• osmosis method


  1. use a cork borer to cut 5 potato cylinders, and trim them so they are all about 3cm, record the mass and length of the potato cylinder
  2. measure 10cm3 of 1.0M sugar, pour it into a boiling tube (label it)
  3. repeat (step 2) with 0.75M, 0.5M, 0.25M sugar
  4. measure 10cm3 of distilled water and pour it into 5th boiling tube
  5. add a potato cylinder into each boiling tube
  6. leave these overnight
  7. remove the potatoes from the boiling tubes, blot them with dry paper towels
  8. remeasure the lengths and mass potatoes, record the findings
  9. calculate the changes in length and mass
• risks of osmosis practical


  • hurt yourself with the cork borers
  • hurt someone with water and electrical balance
• photosynthesis method 


  1. set up test tube rack containing a boiling tube 10cm away from a light source
  2. fill the tube up with sodium hydrogencarbonate solution and place a piece of a plant in the tube
  3. start the stop watch, record the amount of bubbles produced in a minute, for 5 minutes
  4. repeat step 2 and 3 twice to record the mean
  5. then repeat step 1 - 4 with 20cm, 30cm, 40cm distance between boiling tube and light source
• risk of photosynthesis practical


  • concentration of solution should be low to keep it from being a hazard
  • careful with glassware
  • lamp might get hot
  • careful with water and electrical equipment
• enzymes method

  1. place a drop of iodine solution into each depression on the spotting tile
  2. set up 4 water baths, one with ice, one at room temperature, one at body temperature, one above 50º
  3. measure out 5cm3 of starch solution (using syringe) into 4 test tubes, place one test tube in each water bath
  4. measure out 1cm3 of amylase solution (using syringe) into 4 different test tubes, place one test tube in each water bath
  5. leave them in until the test tubes in the same water bath become the same temperature at the water bath - measure this with a thermometer, make a note of these temperatures
• enzymes method (pt2)


  6. pour the amylase solution into the test tubes with starch solution and mix with a glass rod

  7. remove one drop of the mixed solution on the end of the glass rod and place on the first depression of the spotting tile with the iodine solution, start the stopwatch (time zero)

  8. using the end of the glass rod remove one drop onto the next depression in the spotting tile every minute

  9. continue until the iodine solution no longer turns black - starch is broken down

  10. record the temperature of the water bath and the time taken for the starch to be broken down
• risks so enzymes practical


  • safety goggles - iodine solution can irritate
  • careful with hot water
  • careful with water and electrical equipment