Catalase is an enzyme that can be found in various living organisms exposed to oxygen, such as vegetables, fruit or animals. It catalyses the dissociation of hydrogen peroxide to water and oxygen. In living organisms, catalase protects the cell from oxidative damage. One catalase molecule can convert approximately 5 million molecules of hydrogen peroxide to water and oxygen each second.
This experiment was carried out by Vivien, Livia and Artem in order to aknowledge, which of different nutritions have the greatest concentration of catalase. This study is important to “Brave New World”, because catalase and Hydrogen Peroxide may be used to supply us with oxygen during the journey to Kepler 62E. If we take the most efficient catalyser, then we use less volume and, which is more valuable, mass capacity of the spaceship.
- Set up the apparatus as shown in the photograph.
- Blend the reagent (potato/carrot/live/oats).
- Weigh 5g of reagent three times.
- Put the 5g of it in three different boiling tubes.
- Pour 25 ml of Hydrogen peroxide into a measuring cylinder.
- Pour out the 25ml of hydrogen peroxide into the boiling tube with the 5g of raw potato and put the rubber bung on top of the boiling tube.
- Start the timer and wait 90 seconds, remove the rubber bung.
- Measure the amount of oxygen educed into the measuring cylinder.
- Repeat for two other samples.
- Repeat step 1 – 9 with other samples.
- Make sure to clean everything up and work with disinfection as you are working with an oxidant.
Apparatus and chemicals:
- 15g of Carrot
- 15g of Oats
- 15g of Potato
- 15g of Liver
- 250ml beaker
- 4 boiling tubes
- 1 stand
- 1 claw
- 1 connecting tube
- 1 rubber bung
- 25ml measuring cylinder
- 100/500ml measuring cylinder
- Wear gloves, goggles and lab coat; tie your hair up.
- As you’re working with equipment made out of glass, you need to be careful not to break it.
- Make sure that the apparatus is constructed well. Make sure that no connections are loose; otherwise it can break during the experiment.
Don’t drink the hydrogen peroxide. (!)
We conclude from the results that the amount of Oxygen built was very different in the samples. The highest reaction rate can be observed in the experiment with liver. 500cm3 of Oxygen has been formed in even under 90 seconds, on average 28 seconds precisely. Therefore it is necessary to use a larger measuring cylinder. Moreover, no oxygen at all has been built in the sample with oats. The sample with the potatoes produced an average of 51cm3 of oxygen in 90 seconds, but with large amounts of foam; the reaction with the carrots formed an average of 50cm3.
Sources of errors are inaccuracies in measuring the amount of oxygen after 90 seconds. Also the temperature of hydrogen peroxide varied and could have had an impact on our results. Another error could occur when starting the stopwatch. You have to decide whether you start it once all of the hydrogen peroxide is added to the sample or once you start adding the hydrogen peroxide to the sample. Otherwise inaccuracies can follow.
As Catalase breaks down hydrogen peroxide into Water and Oxygen we can conclude that when a lot of oxygen is formed, there must me a high amount of catalase present in the tissue of the sample. The reaction works as the following:
2 H2O2 → 2 H2O + O2
The more oxygen has been built, the higher is the concentration of catalase in the sample. Therefore we conclude that liver has the highest concentration of catalase. Oats have no catalase at all, whereas both carrots and oxygen have a more or less similar amount of catalase.