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

Investigating the effect of enzyme catalase concentration on hydrogen peroxide.

Extracts from this document...

Introduction

SC1 Plan INVESTIGATING THE EFFECT OF ENZYME CATALASE CONCENTRATION ON HYDROGEN PEROXIDE. PLANNING. Background Information: Firstly it must be established that enzymes are protein catalysts. The definition of an enzyme is that it takes part in a chemical reaction but still remains intact after the reaction and is hence not spent. There are two types of enzyme reaction, these can be separated into catabolic and anabolic, anabolic reactions involve growth (i.e. photosynthesis) whereas catabolic reactions involve an enzyme breaking down a substance, for example digestion where organic compounds are broken down in respiration. One thing that all these chemical reactions have in common is that they take place in aquatic conditions. Enzymes have active binding sites, which will fit only certain substrates and thus, they are said to be substrate specific. Enzymes are not destroyed but merely denatured at certain temperatures or by certain pH levels. Temperature denaturisation takes place at temperatures above 60�c but in certain human enzymes it is 45�c. Most enzymes will work at optimum efficiency at around pH 7, which is considered neutral. At a certain or pH the active site of the enzyme may have been changed in shape, this change is likely to be irreversible, however, after the pH changes the enzyme can be reversed back. If the temperature is increased without exceeding the denaturisation barrier, this can lead to an increase of kinetic energy in the reaction between the substrate and the enzyme molecules, this can be explained as resulting in a greater collision rate, this speeds up the rate of the reaction. An accepted figure for this rate of increase is that for every 10�c gained; this results in the reaction rate doubling. Also, by increasing the enzyme or substrate quantity, this may result in the increase of the reaction rate as more collisions take place in less time. The enzyme catalase is present in all living tissue. Catalase breaks down the chemical Hydrogen Peroxide (H2O2) into the harmless chemicals Water (H2O) and Oxygen (O2). ...read more.

Middle

Results: Results Table. Size of potato strip Bubbles given off in first minute Bubbles given off in second minute Average quantity of bubbles given off in first minute Average quantity of bubbles given off in second minute 2 4 3 4 3.5 4 10 8 10.5 8.5 6 20 14 21 14.5 8 22 16 22 14.5 10 19 14 18 13.5 12 28 18 28 19 Results. At the beginning of the experiment the room temperature was noted to be 19�c and the pH was 6. After the hydrogen peroxide was added, the liquid began to show signs of activity in frothing and bubbling, this was an obvious sign that oxygen was being produced and this was confirmed by the produced oxygen appearing in the form of bubbles at the end of the delivery tube and into the 10ml of water. If there had been more time for the experiment it is likely that there would have been no hydrogen peroxide but merely water since it would have been catabolically broken down into two natural substances, well known by man, oxygen and water- produced by catalyse enzymes breaking down some potato cells. More specific results are shown in the tables above. Number of potato discs Time taken for first bubble to emerge for first reading (secs) Time taken for first bubble to emerge for second reading (secs) 2 55 52 4 39 35 6 20 25 8 30 36 10 27 25 12 19 17 Analysing Evidence. From the graph it is possible to see that between 4-8 potato discs the number of bubbles produces increases from 9 bubbles produced on average in two minutes to 19 bubbles on average in two minutes by 8 potato discs but the shape of the graph suggests that from 8-10 the number of bubbles produced begins to drop but then suddenly rises. Thus, it would be possible to make a potential conclusion that the dependent variable begins to increase as the independent variable increases and then ...read more.

Conclusion

For my purposes, I believe that my results were accurate but I would not base any further scientific experimentation on merely my results but maybe culminate more to find an average. My first concern about this experiment is that by taking all the readings from one source of potato, it is possible that the potato I took my readings from was defected and so all my readings will be from an impure source which may have been catalyse deprived or abnormally catalyse rich and so I would repeat the same experiment but with two sources of potato just to ensure that the readings are similar for potatoes since I have no justification that my potato is the stereotypical potato. I would also use more complicated apparatus since the apparatus is simple and easy to use but it would be possible to find a point to sacrifice complication for improving the accuracy of one's readings. I felt that the experiment could have been kept in a temperature bath just to ensure that the temperature was constant throughout since from the background information I learnt that enzymes are affected by temperature. Also, although I carried out a pre-investigatory trial to decide and help to plan a method I would have preferred to do another one just to confirm any variables for my ultimate experiment. I believed that the range should have been extended but on the other hand one had to take into account human resources and time. I believe that the results were slightly limited due to time and the surface area was affected due to the lack of space in the boiling tube and so this would have affected the experiments results. Thus, the range should have been extended in order to see the shape over more readings and I would have liked to taken each reading over more time just to see the effect. Thus, the recommendations in the paragraph are the ways in which I believe that the experiment could be improved for anyone doing the experiment. ...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 Life Processes & 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 GCSE Life Processes & Cells essays

  1. To investigate the effect of enzyme concentration on the activity of catalase in potato ...

    an increase in enzyme concentration has no effect. In the experiment there may be an uneven distribution of catalase in each potato and different potatoes may have different concentrations of enzymes. You can vary the enzyme concentration by altering the number of equal sized discs of potato that contain the Catalase, in the reaction.

  2. Factors affecting the activity of potato catalase on hydrogen peroxide.

    I will use these concentrations, because they are equally dispersed and so I will see the gradual change in between them, that way I will compare the amount of water and oxygen produced in each one. We will cut all the potatoes with the same cork borer size, cut them

  1. Investigate the effect of enzyme concentration on the activity of catalase in potato tuber ...

    an increase in enzyme concentration has no effect. In the experiment there may be an uneven distribution of catalase in each potato and different potatoes may have different concentrations of enzymes. You can vary the enzyme concentration by altering the number of equal sized discs of potato that contain the Catalase, in the reaction.

  2. Investigate the effect of temperature on the activity of catalase (from potato)

    Fair testing: While conducting the experiment, it has to be taken into account that a few variables will have to be controlled so as to ensure that the test is fair. 1. The PH of the reactants should be kept constant.

  1. For my coursework I will be performing an investigation into an experiment using hydrogen ...

    I will use the temperatures 10�C, 20�C, 30�C, 40�C, and 50�C to get varied results. 4. Instead of using a measuring tube to measure 25cm� of hydrogen peroxide, I will be using a syringe or pipette because it will be more accurate.

  2. For my coursework I had to study enzymes (catalysts) and the rate of reaction ...

    was higher than that of what I was using. Needless to say however, the results still prove my prediction to be correct and also mean that the general experiment was a success, despite there being some minor setbacks. Moreover I can also conclude that my results are reliable and accurate

  1. Stephen Blackpool: The Pathetic Figure.

    The setting around the Old Hell Shaft increases compassion for him. The pit is so deep and dark, and the wind blows idly over it. Everybody mourns, cries and feels pity for him. Finally he is helped to get out of the Old Hell Shaft.

  2. Investigating the Effect of Enzyme Concentration on Rate of Reaction.

    This is true until the added enzyme molecules don't work at a maximum rate, due to reasons such as a low substrate concentration. If a point such as this arose during my experiment, the graph would begin to curve from the gradient towards a horizontal line.

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