Bio Method
Student method A
Purpose
To investigate how enzyme concentration can
affect the initial rate of reaction.
To develop experimental and investigative skills,
including risk assessment.
What do you think will be the effect of reducing the concentration of the protease enzyme on the rate of breakdown of the protein found in milk powder? Use scientific ideas to support your idea (hypothesis).
Safety
All enzymes are potential allergens. Handle with care to minimise skin contact and inhalation.
Procedure
1 Pipette 2 cm3 of protein solution into a cuvette.
2 Pipette 2 cm3 of the protease solution into the cuvette. Mix thoroughly and immediately
put into the colorimeter and start the stop clock.
3 Measure absorbance at suitable time intervals for 5 minutes or until there is little change
in reaction.
4 Discard the content of the cuvette and rinse with distilled water.
Student method B
Purpose
To investigate how enzyme concentration can
affect the initial rate of reaction.
To develop experimental and investigative skills,
including risk assessment.
Catalase is an enzyme that occurs in most plant and animal cells. It catalyses the reaction:
2H2O2 →2H2O + O2
What do you think will be the effect of reducing the concentration of breakdown of the enzyme catalase on the substrate, hydrogen peroxide? Use scientific ideas to support your idea (hypothesis).
The rate of reaction can be measured by determining the volume of oxygen gas produced in a unit of time using the apparatus shown in Figure 1. Potato tissue provides a source of catalase.
Safety
Hydrogen peroxide is corrosive,