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

Determining the rate of action of an enzyme (CONCENTRATION)

Extracts from this document...


Determining the rate of action of an enzyme Skills to be assessed: Design, Data Collection & Processing and Conclusion & Evaluation Aim: The purpose of this investigation is to experimentally determine the effect a change in substrate concentration, Hydrogen Peroxide, (H2O2) will have on the rate of action (measured in time taken to surface due to buoyancy of O2 gas)of an enzyme (Catalase). Background: The human body functions due to the action of enzymes which speed up chemical reactions within the body by lowering the activation energy of a reaction. Hydrogen Peroxide is produced in large amounts within the human body, most notably within the liver. Hydrogen Peroxide is a by product of various reactions within the body. It is a toxic chemical and in high concentrations is poisonous to the body systems. Its prolonged presence would ultimately destroy the body's cells by inhibiting metabolic reactions. As a result, the body must find a way of ridding itself of this detrimental Hydrogen Peroxide. It does this through the implementation of the enzyme Catalase. Catalase, like all enzymes adheres to the induced fit relationship between Hydrogen Peroxide and itself. Accordingly it acts only on H2O2 initiating a reaction, via lowering the activation energy, that results in the breakdown of this harmful substance into harmless substances which can be either used or excreted by the body. ...read more.


3. Using the marker, indicate on one (1) test tube and one (1) beaker the concentration of 3% Hydrogen Peroxide. 4. Fill the test tube with 25mL of Distilled water. 5. Fill the beaker with 10mL of 3 % Hydrogen Peroxide. 6. Using the pipette take a sample of the 3 % Hydrogen Peroxide and drop five (5) drops into the test tube. 7. Lightly swirl the test tube to combine the two solutions. 8. Using the tweezers, pick up one of the filter paper squares and immerse it in the crushed liver in the mortar and pestle. 9. Using the second pair of tweezers remove any solid forms of liver from the filter paper. 10. Place the catalase doused filter paper into the test tube. 11. On contact with the solution, begin the stop watch. The paper will slowly sink to the bottom, O2 bubbles will begin to form and lift the paper back to the surface 12. Stop the timer when the paper reaches the top of the test tube. 13. Record this time. 14. Repeat steps 3- 13, replacing the 3% Hydrogen Peroxide with each of the other concentrations. Data Collection Results: Figure 1 shows the time taken for each of the filter sheets to surface in seconds Concentration(C) ...read more.


There was a methodical error in making assumptions about concentration accuracies. It was false to presume that the concentrations marked on the bottles were entirely correct, as well that they had not been tampered with or through other courses been altered. The assumptions were rough approximations based on little evidence; hence they quite possibly are the reason for the slightly skewed results. Also, when conducting the experiment considerations were not made as to the consistent quality of the liver/ Catalase. The condition of the liver was not monitored throughout the process which suggests that the enzymes may have been effect by temperature, humidity, and other outside variables. This could results in the denaturisation of the enzymes which would later be used in the experiment and would skew the results, altering the experiments controlled variable and ultimately providing false results. In the future, to account for these errors, a mass spectrometer should be employed so test the exact concentrations of Hydrogen Peroxide, as well as the quality of the distilled water. More drops of substrate could have been added to provide a clearer result. Rather than a mortar and pestle being used to crush the liver, a blender would be more appropriate to ensure a better consistency and eliminate the effects of a changing enzyme concentration. Finally, the results should be duplicated in order to improve the quality of the mean results and to increase the R2 value of the graph. ?? ?? ?? ?? Feb-10 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology 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 International Baccalaureate Biology essays

  1. Peer reviewed

    Enzyme Coursework. Investigation to find the effect of substrate concentration on the rate ...

    5 star(s)

    of the solutions * the temperature of the solutions * the pH of the solutions Aspect 2: Controlling variables Independent variable: the concentration of the hydrogen peroxide solutions will be changed by adding distilled water to hydrogen peroxide (with the aid of a syringe).

  2. Browning Enzyme

    And so the test tubes were taken out at a time ranging from 17 -17.50 seconds. Some test tubes were in the water baths for slightly longer and so this would affect the results I received as the results would be larger than expected.

  1. Investigating an enzyme-controlled reaction: catalase and hydrogen peroxide concentration

    I tried to keep all the variables except for the concentration of Hydrogen Peroxide the same for all the experiments. However, in reality it is impossible to keep all the variables precisely the same. For example: a) There is a slight delay between pouring the Hydrogen Peroxide into the yeast, putting the bung on and starting the stopwatch.

  2. Testing the solute concentration of potato cells

    It is melanin that causes the brown pigments. This situation seems to have no great effect on this experiment. Though the brown color is likely to mean less fresh state, the freshness would not affect the osmosis process of water molecules. Even so, potatoes were all together browned.

  1. Testing the effect of characteristics of leaves on the transpiration rate of * ...

    per minute per m2 of four different species (*Rubiaceae, Verbenaceae, Oleaceae, and Rutaceae) Note: the uncertainty of � 0.0001m� for total surface area is from 1 cm� grid paper which was used for counting the surface area of plant species.

  2. Biology- Extended essay. For this research, I investigated the effects of DDT and ...

    Through an analysis of these three investigations I will determine the change in the opercular movement of Cirrhinus Cirrhosus. 1. Taking 5 glass beakers arrange them in a line and marked them as: A, B, C, D and E. 2. Fill each beaker with 200 ml of filtered water. 3.

  1. Should Animals have the same rights as Humans? Both animals and humans exhibit behaviours ...

    For example, wild horses (which are prey animals) eat plant materials. They roam large distances to find their food, travel in herds to be safe from predators and eat little and often so that they can run from predators if necessary without being hampered by full stomachs.

  2. How does changing the percentage of sucrose added to yeast affect the rate of ...

    mixed as successfully with all of the cells causing the rate of respiration to not be as high. As we altered this throughout our experiment randomly it would have caused there to be greater variance in my data and thus increased the size of my error bars and decreased the validity of my data.

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