• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

To investigate one factor which affects the way in which the enzyme catalase works.

Extracts from this document...


To investigate one factor which affects the way in which the enzyme catalase works. Aim: To investigate one factor which affects the way in which the enzyme catalase works. catalase Hydrogen peroxide ? oxygen + water 2H2O2 (aq) O2 (g) 2H2O(l) Background: There are three main ways to affect the way and speed that the enzyme catalase works. One is to change the temperature at which it is used. This affects the rate of reaction at which hydrogen peroxide is broken down because enzymes act like inorganic catalysts, and the rate of reaction doubles every 10?c within the temperatures of 0 and 40?, but above this temperature the enzymes effectiveness slows, and then stops as it becomes denatured. The optimum temperature is around 37?c, as this is the average body temperature and enzymes are designed to work in the body. For a reaction to occur, particles need to collide successfully. For a successful collision, molecules need to collide with enough energy to break the bonds. This is called the activation energy. The activation energy level, which is needed, can be lowered by use of a catalyst (in this investigation using the biological catalyst, the enzyme catalase) ...read more.


Fair test: To make this experiment a fair test, I will keep the mass of liver the same each time, and time for 30 seconds each time. I will also try to keep the temperature of the hydrogen peroxide solution at room temperature, as temperature can affect the rate of reaction. I will do this by measuring the temperature before the start of each reaction, not after as the reaction could be endothermic or exothermic. I will try and put the bung on as quickly as possible after the liver goes in so that none, or not a lot of the oxygen escapes without being measured. I will also not shake or stir the hydrogen peroxide and liver at all, as this could increase the rate of reaction due to the substrate particles coming in contact and so being broken down more by the liver. Preliminary work: Before I carried out this experiment I did some preliminary work to decide on what volumes, concentrations and masses to use. For example when using a lot of liver a vigorous reaction occurred so I decided to use 0.2g rather than any higher masses. I decided on the concentration of the hydrogen peroxide as well, as there is enough difference between each concentration for a change in the rate of reaction to be noticed. ...read more.


These can be seen best on my second graph which shows the rate of reaction against the concentration of the hydrogen peroxide. They are at 20% and 60%. These odd results are most likely due to human error. These could be improved by repeating the experiment more times to get more results to compare them with, or as I mentioned earlier by using more accurate equipment like the burette. Although there were these anomalous results, they still followed the general pattern, so I think that from my results I can draw a firm conclusion. To do further work on investigating factors which affect the rate of reaction of the breakdown of hydrogen peroxide, the experiment could be done, but instead of making concentration the variable, changing the temperature each time, or by changing the pH of the solution each time. (Both mentioned in greater detail in my background knowledge). Another thing that could make a more accurate experiment to make a firmer conclusion would be to use a wider range of concentrations hydrogen peroxide. As I mentioned earlier, the molarity of the 100% solution of hydrogen peroxide was 1.76 moles, so by using a higher concentration of hydrogen peroxide, it would have been easier to see the tail off of the rate of reaction at the end of the experiment. Clare Mann 11F 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Patterns of Behaviour section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Patterns of Behaviour essays

  1. Investigate the effect of changing substrate concentration on the rate of the reaction between ...

    Do not misuse any equipment, especially knives, cylindrical cutters and scalpels. Keep such equipment away from the rest of the equipment and from areas of extreme activity. (3) Do not allow any chemicals, like hydrogen peroxide, to make contact with skin, eyes and any other body areas.

  2. Exothermic and endothermic reactions

    This is because when the rock was formed the squashing forces caused all the particles to line up in the same direction. Processes in the rock cycle Rocks can be broken down by the processes of physical weathering and chemical weathering.

  1. Enzymes - show how substrate concentration affects the rate of reaction for an enzyme ...

    Lower concentration of Hydrogen Peroxide Hydrogen Peroxide Active site CATALASE The diagram above shows at a lower concentration there are a lower number of hydrogen peroxide molecules. As result of this there are less frequent collisions hence less product produced in a given time.

  2. The effect of aspirin on the action of bovine liver catalase

    Hydrogen peroxide solutions will be made using various dilutions of 1 mol/dm� hydrogen peroxide. Each will be tested to the most suitable concentration. To carry out the experiment measure 1ml of liver solution, and put it in the test tube.


    Median = 0.537 The above information shows that my degree of freedom is 7, and t stands for 3.20. By using the t-table I can determine whether or not to reject my null hypothesis. As my t-value is greater than the critical figure 1.895 (maintained from the significance level 0.05, degree of freedom 7)

  2. Factors Affecting Enzyme Activity

    0.0 23.0 31.0 36.0 41.0 43.5 43.5 43.5 By looking at these results I can see that the best ratio I have tested so far is the ratio of 10:1 (5cm3 hydrogen peroxide to 0.5 cm3 liver suspension) as it gives me a good spread of results and does not happen so quickly that I cannot take results from it.

  1. The Effect of Catalase in the Breakdown of Hydrogen Peroxide

    An increase in a substrate can give more to the enzymes. As more and more substrates are used up, the reaction slows down to a point that it looks like it is stationary. Less substrate also means that the reaction would slow down.

  2. Investigation into the effect of substrate concentration on the rate of hydrogen peroxide decomposition ...

    Its narrow neck allows it to be sealed easily with a rubber bun. 3. It is of suitable volume to contain the reacting substrate and enzyme. There is not a great range of equipment that could be used for the following tasks, instead of listing alternative equipment I will

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work