Practicals

• Reaction time practical

  1. sit person down with arm rested on table
  2. hold ruler vertically between thumb and forefinger, making sure zero like is level with thumb, let go without any warning
  3. person should catch ruler as quick as they can, measure where top of thumb is the higher the number the slower the reaction time
  4. repeat several times and then calculate mean
  5. have the person being tested drink caffine, after 10 minutes repeat experiments again
• Plant growth

  1. put 10 cress seeds into petri dishes each lined with moist filter paper
  2. shine light on plants from different angles
  3. leave cress seeds for 1 week
  4. you should see that the plant grows towards the light
• Effect of temperature on the rate of decay

  1. Measure 5cm³ of lipase solution

  2. Measure 5cm³ of milk and add 1cm³ into each test tube

  3. Add 5 drops of phenolphthalein indicator into test tubes of milk

  4. Measure 7cm³ of sodium carbonate solution and add to milk test tube

  5. Put both test tubes (milk and lipase) into premade water bath of 30°C, leave them until they reach 30°C

  6. Add 1cm³ of lipase to milk test tube and start timer

  7. When solution loses pink colour stop timer

  8. Repeat with different temperatures, do 3 times and calculate mean for each temperature

  9. Calculate rate of decay (1000 ÷ time)