To Prepare An Enzyme Immobilisation And Examine Its Application

Question 1

What is an immobilised enzyme?

Answer 1

Immobilised enzymes are enzymes that are attached, or fixed, to each other, or to an inert material

Question 2

Give one example of using immobilised enzymes.

Answer 2

Can be reused

Question 3

Name the enzyme or cell that you used.

Answer 3

Yeast = enzyme is sucrase

Question 4

Describe how you immobilised that enzyme or cell.

11

Answer 4

Add some sodium alginate to water in a beaker

Stir the mixture until it forms a smooth paste and leave to soak for five minutes

Add some yeast to water in a second beaker

Stir the yeast solution and leave for five minutes

Dissolve some calcium chloride in water in a larger breaker

Pour the yeast solution into the alginate paste and stir to mix thoroughly

Draw some of the resulting mixture into a syringe

Slowly and steadily add a series of alginate and yeast drops from the syringe to the calcium chloride solution

Hold the syringe fairly high above the chloride solution and gently stir the solution to prevent them from clumping

Leave the beads in the calcium chloride solution for 15 minutes

Place the beads in a sieve and rinse them under a rap of running water to remove any yeast cells from outside the hardened beads

Question 5

Outline how you used the immobilised enzyme or cell to examine its application.
(7)

Answer 5

Pour the beads of immobilised enzyme into a separating funnel (use a short piece of drinking straw to prevent the beads from blocking the outlet of the funnel

Add some yeast to water in a beaker and stir

Dissolve some sucrose in warm water

Pour half the sucrose solution into each separating funnel

Test the products by letting them drip onto glucose test strips such as Diastrix

Continue to test until glucose is found coming from each separating funnel

Observe the products in each beaker - the immobilised yeast solution is clear while the other is cloudy

Question 6

Describe how you added the sodium alginate mixture to the calcium chloride solution

Answer 6

Using a syringe add the sodium alginate drop by drop fairly high above the calcium chloride mixture

Question 7

Why were the beads left undisturbed for at least ten minutes before they were rinsed

Answer 7

To allow the beads to harden

Question 8

In which of the beakers will a positive test for glucose first occur?

Answer 8

In the beaker with the non-immobilised yeast

Question 9

Which beaker will contain a colourless solution of glucose?

Answer 9

The immobilised yeast

Question 10

Why will the beaker containing the product from the immobilised yeast be colourless?

Answer 10

Yeast is immobilised so no yeast can fall into the beaker - there is no yeast free in the beaker

Question 11

Name the enzyme used in this experiment.

Answer 11

Sucrose

Question 12

Name the substance used to immobilise the enzyme.

Answer 12

Sodium alginate