• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13

An Experiment to find out the Effect of Temperature on the Enzyme Catalase.

Extracts from this document...

Introduction

An Experiment to find out the Effect of Temperature on the Enzyme Catalase Plan I plan to investigate the effect of temperature on enzyme activity. If I was to carry out this experiment, I would need to carry out an experiment to work out the optimum temperature or range of temperatures at which the enzyme works best. At higher biological temperatures I believe that the enzyme and the substrate would have increased molecular motion and collide more often, hence reaction rate will be higher. However I know that if I use too high a temperature the secondary and tertiary structures are disrupted and the enzyme is said to be denatured. I know that catalase is found in the liver, as it breaks down Hydrogen Peroxide, and most mammalian enzymes work at biological temperatures which range from 37�C - 40�C. This is what I predict my optimum range to be. Variable How Will it be controlled? Why will it be controlled? Catalase I will measure out carefully 0.3cm3 using a 1cm3 micro pipette It will keep the same volume of enzyme in solution in order for the results to be accurate and valid, because if there is more catalase the reaction will occur faster as more enzyme substrate complexes will be formed. Hydrogen Peroxide I will measure out carefully 5cm3 using a 5cm3 graduated pipette It will keep the same volume of the substrate in solution in order for the results to be accurate and valid, because if there is more Hydrogen Peroxide more oxygen will be emitted and an enzyme substrate complex will be formed more often. pH Buffer I will measure out carefully 0.5cm3 using a 1cm3 micro pipette It will keep the pH levels constant in the solution so that the results are accurate and valid, because if there are more hydrogen ions or hydroxide ions it may affect the rate at which the catalase functions. ...read more.

Middle

I did not carry out this part of the plan because I realized that when I seal the system, air will be trapped inside, so the oxygen expelled by the reaction will not actually reach the gas burette, instead it may just force the air present inside the system into the gas burette, hence I thought that my glowing splint would not relight as it is unlikely to be exposed to pure oxygen. Another reason I did not test for oxygen is because in some of the reactions only a small amount of oxygen would be released and may not be enough to re-light the glowing splint, in addition the oxygen collected woud be located at the top of the gas burette and my splints were too short to reach that far up the gas burette. I controlled the pH by adding 0.5cm3 pH 8 buffer to every reaction so that hydrogen ions or hydroxide ions were kept constant because they may affect the rate at which the catalase functions. I controlled the volume of catalase each time because if there is more catalase in a specific reaction than in the other reactions it will occur faster as more enzyme substrate complexes will be formed. I controlled the volume of the Hydrogen Peroxide each time because if there is more Hydrogen Peroxide in a particular experiment more oxygen will be emitted, because enzyme substrate complexes will be formed more often. I controlled the light intensity by keeping the Hydrogen peroxide in a brown jar and conducting the entire experiment in the same room. If the light intensity was varied it may have forced the Hydrogen Peroxide to break down faster. Results Preliminary experiment results to work out optimum pH around neutral conditions, at room temperature: ph 6 Time in seconds 1st attempt Oxygen released (cm3) 2nd attempt Oxygen released (cm3) 3rd attempt Oxygen released (cm3) ...read more.

Conclusion

So it would not have affected any conclusions that I have drawn. The high reading of oxygen evolved after 15 seconds at 25�C on one of my graphs may be from the force at which the Hydrogen Peroxide was added to the catalase and pH buffer. This could have affected the results as if the syringe was emptied quickly it would mix with the catalase in the test tube faster, giving the catalase more Hydrogen Peroxide to break down at an earlier point in time. This had an affect on the earlier points on my graphs, but not on the general pattern and hence would not have affected any conclusions that I have drawn. If I did this experiment in the future I might unhook the delivery tube each time I wanted to measure a reading from the gas burette. This would help as I would have more accurate readings by creating more time to collect the measurements. I would also use a more accurate syringe to measure out the Hydrogen Peroxide so that the same amount of substrate was added to each reaction, thus giving me more reliable results. It would also help to support the conclusions that I have drawn from this experiment. The evidence I collected is what I expected to find, however in my opinion it is not enough to produce a firm valid conclusion. The maximum yield of oxygen at 35�C is roughly normal although I do expect to find that the optimum would be a little higher, than the max yield that I obtained. In order to produce a firm valid conclusion I would have to repeat the experiment on the temperatures between 35�C-45�C, so that I could find out the exact optimum temperature. Also I would have to conduct the experiment at lower temperatures, on the rising curve, so that I can obtain a full reaction rate curve. I could have also measured the pH in every reaction instead of just relying on the pH buffer to do its job. This would have further validated the results I obtained. ?? ?? ?? ?? ...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. Marked by a teacher

    The effect of temperature on the enzyme Catalase.

    4 star(s)

    What I will need to do is put 2ml of Catalase enzyme into a test tube, and then place the test tube into a water bath. The water bath temperature will be between 15�c and 50�c but in denominations. This will give me a good range of temperatures including body (37�c)

  2. Marked by a teacher

    The effect of temperature on catalase activity

    3 star(s)

    If the molecular structure is disrupted, the enzyme ceases to function as the active site no longer accommodates the substrate. The enzyme is denatured. To control this variable, the temperature was maintained at a fairly constant level that allowed the enzyme to work effectively (room temperature, approximately 23�C).

  1. An experiment to find of the isotonic point of root vegetables cells in contents ...

    best fit for each root vegetable have the same range in which the mass and width are covered. Therefore to work out the precise point of incipient plasmolysis I will work out the area covered in the range and divide it by 2 and then add this value the first value of the range.

  2. To investigate the rate at which hydrogen peroxide is broken down by the enzyme ...

    resulting in more chemical reactions being caused by successful collisions between the active site of the catalase and the hydrogen peroxide. I would also expect the highest concentration of the catalase to give a greater rate of reaction more quickly than the lower concentrations of catalase because it contains the most molecules.

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

    Doubling the number of enzyme molecules will double the number of active sites available for the substrate to bind with, therefore a doubling of the rate of reaction up to a certain point. HoIver, as higher concentrations of enzyme are used, over half the substrate molecules will be bound to

  2. How does a change in temperature effect the activity of the catalase enzyme on ...

    When 1 minute was reached I pulled the rubber tubing from underneath the measuring cylinder and took the reading. I carried out the same procedure each time I was testing and only changed one variable that was the temperature of the hydrogen peroxide.

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

    The graphs provide a Graphical analysis of the results. Agreed Method Commentary As an agreed method used by everyone, the class results can be used for statistical analysis. Some peoples' results will have anomalies, for a number of reasons, and a graph of the class' average rate of reaction would

  2. Investigating the effect of the Temperature on the Enzyme Catalase when it reacts with ...

    All this colliding of particles that is taking place has a theory background to it, this is known as the Collision theory. The rate of reaction depends on how hard the reacting particles collide with each other. The harder and more often the particles collide the faster the reaction.

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