Additional resources for week 1
A selection of additional resources for teaching about enzymes.
Using enzymes to make creme eggs
This video demonstrates how to make soft-centred chocolates, using enzymes. Students could carry out this practical and if undertaken in a food safe environment, using food materials and following a scrupulous hygiene regime, produce chocolates that could be eaten.
This practical provides a real-world application of the use of enzymes, which will be of interest to many students (chocolate!).
Fruit Juice Production
Fruit juice can be extracted from a wide variety of fruits. This can be done by simply squeezing the fruits but it is more common to use enzymes to increase the volume of juice produced and the speed of extraction. Enzymes are expensive products and clearly juice manufacturers want to minimise their costs by using the enzymes at their optimum conditions and therefore maximising their effectiveness and re-using the enzymes where possible.
In this practical students practice making immobilised enzymes and using a colorimeter to compare the effective of different enzymes. They can also compare different methods of extracting the enzymes from waste apple and re-using them.
Microscale investigations of catalase activity in plant extracts
This is a relatively straightforward practical activity that allows students to compare catalase activity across a range of different fruits and vegetables. The protocol uses a deceptively simple, yet very accurate, method to measure the rate of reaction by collecting the oxygen evolved as a product of the reaction.
The whole reaction can be carried out on a very small scale, in a centrifuge tube.
An enzyme extract is adsorbed to filter paper discs. These discs initially sink in a hydrogen peroxide solution, but then float to the surface as the oxygen produced gets trapped in the paper fibres. The time taken for the discs to rise is measured.
As the protocol uses small samples of tissue it is also possible for students to take a series of samples across one particular plant organ (for example a diseased vegetable) and investigate the difference in catalase activity in different areas
Improving Teaching and Learning in Engineering
look at page 16
