RP1

• what is the control when measuring enzyme activity?

  identical set up but with the enzyme solution replaced with distilled water or boiled enzyme solution
• how can results of the practical on enzyme activity be used to find the initial rate of reaction?

  plot results on a graph where rate of reaction is against time

  draw a tangent at 0 time to find the initial rate
• outline the practical method of measuring the effect of temperature on enzyme activity using trypsin and milk

  Immerse equal volumes of trypsin and milk, stored in different test tubes, in a water-bath for 5 minutes for the temperature to equilibrate.

  Mix together and immediately start timing, record the time taken for the milk to be completely hydrolysed (become colourless/ same as the control standard set up).

  Test at least 5 temperatures, with at least 3 repeats at each temperature.
• how is rate of reaction calculate from time?

  Rate of reaction = 1/time
• What is the risk and level of risk associated with handling enzymes?

  Students may have allergic reactions to enzymes, so avoid contact with skin and eyes, wear eye protection.

  Low risk.