1.4.9 Describe how enzyme concentrations can affect the rates of reactions and how this can be investigated practically by measuring the initial rate of reaction.

(the rate of reaction slows down as substrate is used up)

Procedure:

• prepare a range of enzyme concentrations, at least five
• pipette 5cm3 of protein suspension (egg albumin or milk) into 5 test tubes. 
• substrate concentration (protein suspension) should not be limiting at the start of the experiment.
• mix the enzyme and the substate thoroughly and immediately start the stopwatch. 
• measure the dependent variable by measuring the time taken for the protein solution to clear at each of the enzyme concentrations. 
• temperature should be kept constant by using a water bath maintained at 30 degrees and the pH maintained constant using a buffer solution.
• repeat the experiment at each enzyme concentration and find the average.