RP1: Rate of enzyme controlled reaction

• Factors which affect enzyme controlled reactions


  Temperature, pH , enzyme concentartion and substrate concentartion
• Hazard, risk and precaution from broken glass


  Cuts from sharp object

  Keep away from edge of desk

  Low
• Hazard, risk and precaution from water bath/ hot liquids


  Scalding

  Use tongs/ eye protection

  Low- run under cold water
• Hazard, risk and precaution from enzymes


  Allergies

  Avoid contact with skin/eyes

  Goggles

  Low
• Conclusion of practical if temperature


  • As the temperature increases from 10°C,​ kinetic energy increases​​ so more enzyme-substrate complexes ​​form. This means that the rate of reaction increases​​ up to the optimum temperature.
  • At temperatures beyond the optimum, ​bonds​​ in the enzyme ​tertiary structure break​​, which changes the shape of the​ active site​​This means that the substrate and enzyme are no longer ​complementary​​.
• Explain why the student did not add a buffer to the pH solution


  As measuring change in pH in experiment
• Two variables the student controlled in experiment while investigating the effect of lipase concentration on the hydrolysis of lipids

  Temperature

  Volume of suspension of lipids
• Give one other suitable control for experiment

  Boiled lipase solution
• Explain results shown in graph of lipase experiment


  Fatty acids produced.

  Curve levels off as all of substrate is used up
• The student repeated the lipase experiment with a higher concentartion of lipase solution. Explain results you would expect to find


  Faster fall in pH and levels off at same point

  More E-S complexes formed

  Same amount of fatty acides produced
• Explain why cats were used in investigation as model organisms


  Mammals so likely to have same physiology as humans

  Can use a large number

  Small enough to keep in lab
• How is a control set up when measuring enzyme activity?


  Replace enzyme solution with distilled water or boiled enzyme solution