Neutrase® is an enzyme used to hydrolyse proteins in solution. When this enzyme is added to a 2% protein solution, the mixture changes from white to colourless.
A student investigated the effects of copper sulfate and potassium sulfate on Neutrase® activity.
Four reaction mixtures were prepared in test-tubes A to D. Test-tubes A to C each had equal volumes of protein solution and $0.1\,\text{cm}^3$ of copper sulfate or potassium sulfate solutions. Test-tube D contained the same volume of protein solution and $0.1\,\text{cm}^3$ of water.
$0.5\,\text{cm}^3$ of a 1% Neutrase® solution was added to test-tube A and it was placed straight into a colorimeter. The colorimeter measured the intensity of light absorbed by the solution (absorbance) for 100 seconds. The same procedure was carried out with the other reaction mixtures, B, C and D.
The outcomes are displayed in Fig. 3.1.
(a(i))[2]
Suggest and explain why tracking the absorbance of the reaction mixture for 100 s is a suitable way to determine Neutrase® activity.
(a(ii))[5]
Using Fig. 3.1 as reference:
• describe the effect of copper sulfate solution and potassium sulfate solution on Neutrase® activity
• suggest explanations for the effects you described.
(b)[2]
Neutrase® can be immobilised in alginate. Immobilised Neutrase® is used in the food industry to make foods with a high nutritional content.
Explain the advantages of using immobilised enzymes, such as Neutrase®, rather than using the same enzymes free in solution.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The enzyme hydrolyses protein into smaller peptides or amino acids” …