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

The Effect of Substrate Concentration on the Rate of Decomposition of Immobilised Liver Catalase.

Extracts from this document...


The Effect of Substrate Concentration on the Rate of Decomposition of Immobilised Liver Catalase Background Information: When the chemical Hydrogen peroxide (H2O2), is introduced to the enzyme Catalase, it is decomposed into to products, Oxygen (O2) and Water (H2O). This is shown by the equation: 2H2O2 (l) 2H2O (l) + O2(G) AIM: I am aiming to find out whether increasing the concentration of substrate (H2O2) affects the rate at which Oxygen is produced from the decomposition reaction. I will do this by counting the number of bubbles of Oxygen produced from several samples over a set period of time. I have established that: The Independent variable = Substrate concn The Dependant variable = Production of O2 The variables: The variables that have to remain constant are: * Concentration of catalase (5% liver extract) * Volume of Hydrogen Peroxide * PH * Temperature (controlled by water bath) * Time (2 min. period p/experiment) PLANNING I am going to be changing the concentration of H2O2 that the beads of catalase will be added to (making it an immobilised enzyme). ...read more.


* When you have used up all of the mixture, with a sieve collect the beads and rinse them off with a little distilled water. METHOD: 1. Set up apparatus shown below: 2. To make the desired concentration of hydrogen peroxide, get a 10ml measuring cylinder and for 10% place 1ml of hydrogen peroxide in with 9ml of distilled water. (CARE: Hydrogen peroxide is an irritant, keep away from eyes and clothes, as bleaching can occur.) 3. Then place 20 beads into the boiling tube of Hydrogen Peroxide and insert the bung of the delivery tube back in and start the timer. 4. Over a period of 2 mins. Count the number of bubbles produced from the reaction. 5. After, repeat the experiment with 20% and 30% concentrations. 6. When gaining the results for all three concentrations, do three repeats per concentration to gain reliable results. RESULTS: This graph shows the relationship that is present between the results. As the concentration of Hydrogen Peroxide is increased (coloured bars) the amount of Oxygen increases also. The concentration that was most effective on oxygen production was 40% (dark purple), with roughly around 140 bubbles produced in 2 minutes. ...read more.


Because all enzymes are proteins, they are consisted of amino acids, and when these long chains fold up the form an active site, which then can react with substrates. If too much heat energy is added, the molecule is vibrating with such energy that weak Hydrogen bonds that hold the tertiary structure of the protein together are broken. These results in reshaping of the active site, that is very specific to certain substrates, and therefore becomes denatured. Although increasing the concentration of the substrate increases the rate of decomposition, if the concentration is increased too much the active sites on the enzymes will be saturated (occupied by substrates), this would then decline the rate at which Oxygen was produced. I think the results that I gained show a clear trend forming from reliable results. If I were to repeat this experiment again I would like to prove whether what I can tell with my own scientific knowledge, that if I carried on increasing the concentration of Hydrogen Peroxide to a point where there were more substrates than enzymes, I would see a gradual decline in the amount of oxygen produced. If I carried out such an experiment I would expect to see the pattern on the graph to look like this: ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells 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 AS and A Level Molecules & Cells essays

  1. In this experiment I will be investigating and analyzing the factors affecting the rate ...

    I am doing and what I intend to do for my actual practical. The results showed me that as the temperature goes higher the rate at which catalase works at increases, until the enzyme cannot work anymore. At this stage it is said to be denatured.

  2. The effect of Copper Sulphate concentration on Catalase activity on Hydrogen Peroxide.

    of the equal sizes of the potato tubes, but I never actually measured the Catalase concentration itself. A way in which this could be done is to use yeast instead of potato tubes, and test and adjust the catalase concentrations in it with the use of a syringe and by adding water if necessary.

  1. Investigate how concentration of the enzyme catalase in celery tissue alters the rate of ...

    By liquidising celery extract, the membrane-bound catalase is released as cell membranes are physically broken, "A native, membrane-bound catalase molecule can detoxify nearly 100 million H2O2 molecules per second! (Isolated "purified" catalase is only about 10% as fast.)", but the use of actual celery is hard to implement because more factors are introduced.


    No oxidised NAD forms so oxidation reactions (such as the oxidation reaction that converts the 6C Citrate to 5C oxoglutarate,) which occur in the Krebs, cease. This is because these reactions require oxidised NAD to remove and accept electrons/hydrogen ions from the molecules, causing the molecules to become oxidised while becoming reduced themselves.

  1. the effect of substrate concentration on the rate of an anzyme reaction

    At these very high temperatures the enzyme can become denaturated. This means the enzyme's active site has become permanently damaged. The concentration of the enzyme solution also affects the rate of an enzyme reaction. If there are more enzyme molecules than substrate molecules, then the substrate would be a limiting

  2. Investigate the effect of the concentration of catalase on the rate of decomposition of ...

    All enzymes have an optimum pH depending on where they are based, intracellular or extra cellular. Substrate concentration: The higher the concentration that faster the rate of reaction, which is until they are working as fast as they possible can.

  1. Investigating the effect of concentration change in Immobilised enzymes

    produce an enzyme with altered properties * The enzyme can be removed and reused over and over again * The enzyme may be more stable at extreme pH or temperatures and it may therefore last longer * The enzyme does not denature * The product is not mixed in with the enzyme and doesn't need separation which reduces costs.

  2. the effect of catalase concentration on the breakdown rate of h2o2

    Another example is hydrogen peroxide, H2O2, which breaks down into water and oxygen. It is a powerful oxidising agent produced in the body, as a by-product of fatty acid and cholesterol oxidation, and is produced by white blood cells to kill bacteria.

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