1 The effect of temperature on the rate of reaction of an
enzyme controlled reaction
The hydrolysis reaction of Casein by Trypsin:
Enzymes are biological catalysts for metabolic reactions, both at a cellular level and the
organism as a whole. They speed up reactions by lowering the activation energy and
thereby increasing the rate of reaction. Trypsin is an enzyme that digests the protein Casein
which is found in milk. The solution changes from milky to clear if Casein is digested when
Trypsin is added to a dilute solution of milk powder.
The experiment aims to investigate the effect of the variable temperature on the rate of
reaction of Trypsin digesting Casein.
Independent variable: Temperature
Dependent variable: The time taken for the solution to go clear (for Casein to be digested)
Enzyme: Trypsin
Substrate: Casein
The experiment needs to be controlled so that the results are accurate. The enzyme and
substrate concentration and volume need to be controlled. Furthermore, the buffer solution
used to control the pH and its volume should be kept the same. Safety needs to be taken
into consideration so general lab rules need to be followed. For example, goggles and
protective gloves as well as lab coats should be worn.
Temperature Time in seconds Rate of reaction
20 374 2.674
30 289 3.460
40 54 18.518
50 113 8.849
60 121 8.265
enzyme controlled reaction
The hydrolysis reaction of Casein by Trypsin:
Enzymes are biological catalysts for metabolic reactions, both at a cellular level and the
organism as a whole. They speed up reactions by lowering the activation energy and
thereby increasing the rate of reaction. Trypsin is an enzyme that digests the protein Casein
which is found in milk. The solution changes from milky to clear if Casein is digested when
Trypsin is added to a dilute solution of milk powder.
The experiment aims to investigate the effect of the variable temperature on the rate of
reaction of Trypsin digesting Casein.
Independent variable: Temperature
Dependent variable: The time taken for the solution to go clear (for Casein to be digested)
Enzyme: Trypsin
Substrate: Casein
The experiment needs to be controlled so that the results are accurate. The enzyme and
substrate concentration and volume need to be controlled. Furthermore, the buffer solution
used to control the pH and its volume should be kept the same. Safety needs to be taken
into consideration so general lab rules need to be followed. For example, goggles and
protective gloves as well as lab coats should be worn.
Temperature Time in seconds Rate of reaction
20 374 2.674
30 289 3.460
40 54 18.518
50 113 8.849
60 121 8.265
