prac 1 enzyme controlled reaction

• what are the factors that affect enzynme activity?

  • enzyme concentration
  • substrate concentration
  • temperature
  • pH
• how is a control set up in a practical measuring enzyme activity?

  replace the enzyme solution with distilled water or boiled enzyme solution
• how can the results measuring enzyme activity be used to find the initial rate of reaction?

  plot results on a graph of rate of reaction against time

  draw a tangent at time = 0 to find initial rate
• what is the procedure used to measure the effect of temperature on enzyme activity - trypsin and milk

  test 5 temperatures, repeat each temperature 3 times

  put 10 cm3 of milk solution to 5 boiling tubes

  add 2 cm3 of trypsin to 5 other boiling tubes

  stand the tubes in each temperature water bath to acclimatise

  add the trypsin and milk and replace in the water baths

  measure the amount of time it takes the solutions to go clear
• how is the rate of reaction calculated from time


  rate of reaction = 1 / time
• how is enzyme activity affected by temperature?

  temperature increases - kinetic energy increases

  rate of reaction increases

  at a certain temperature, bonds in the tertairy structure break

  enzyme denatures

  rate decreases
• what is the risk of handling enzymes?

  allergic reactions

  avoid contact with skin, goggles