RP1 enzyme reaction

• rate of enzyme-controlled reaction can be affected by

  • temperature
  • pH
  • substrate concentration
  • enzyme concentration
• method

  1. make two control samples
  2. put milk in 3 test tubes and in a water bath at 10 degrees
  3. add trypsin
  4. record how long it takes for milk samples to be fully hydrolysed and colourless
  5. repeat at different temperature (20, 30, 40, 50)
  6. find mean time for milk to be hydrolysed at each temperature and calculate rate of reaction
• rate of reaction = 1 / mean time
• Control samples

  1. add milk and distilled water to indicate absence of enzyme activity
  2. add milk and hydrochloric acid to indicate colour of completely hydrolysed sample
• broken glass is low risk can cause cuts so take care

  can cause cuts so take care

  in emergency elevate cuts, do not remove glass from wound, seek medical attention
• hydrochloric acid is low risk

  may cause harm/irritation in eyes or cuts

  wear eye protection and avoid contact with skin

  in emergency wash skin, flood eye and cuts with cold water
• Hot liquids are low risk

  can cause scalding so handle with care, use tongs to remove boiling tubes and wear eye protection

  in emergency run burn under cold water and seek medical attention
• enzymes are low risk

  some may be allergic so avoid contact with skin and eyes, wear eye protection

  in emergency seek assistance
• after experiment, plot a graph of rate of reaction against temperature
• conclusion

  milk contains protein called casein, when broken down, milk turns colourless

  trypsin is a protease enzyme that hydrolyses casein

  as temperature increases so does kinetic energy, more enzyme substrate complexes form so rate of reaction increases to optimum

  above optimum, bonds in tertiary structure break, active site changes shape and enzyme and substrate no longer complementary