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

LR Biology liver enzyme

Extracts from this document...


LAB REPORT: BIOLOGY Title: Cow liver catalase experiment. Question: - Is there enzyme activity? -How is the rate of the following reaction with a low temperature compared to a normal temperature? 2H2O2 (catalase as an enzyme) --> 2H2O + O2 Materials: 1000ml of distilled water, 50g of Cow liver, 1x Bunsen burner, 1x Thermometer, 1x Syringe (1 ml � 0.1ml), Tap water, 1x Syringe needle, 50ml of water peroxide (10vol), 1x Stopwatch, 1x Erlenmeyer flask, 1x Measuring cylinder (ml � 1 ml), 2x Water bath, 1x Thin rubber tube. Variables: Independent: Time (by stopwatch, � 3s) Dependent: Amount of O2 released Controlled: Concentration of catalase solution (50g blended in 1000ml of distilled water), amount and concentration of Water Peroxide (50ml, 10vol), amount of catalase added (1ml in syringe � 0.1ml), initial temperature of the catalase solution, Temperature � 1�C, data values (by the same observer with equal/indifferent criteria of judging). Not controlled: Amount of tap water added and number of ice cubes. Diagram: Procedure: - A solution of 50g of catalase per 1000ml of water was prepared. ...read more.


Data processing: Graph 1.1: Results from the experiment plotted as Time vs. O2 produced This graph shows how at a low temperature, rate is slow due to the poor energy it provides. If this graph could continue (which wasn't possible due to the maximum measurement of the measuring cylinder (100ml)), it would show how the reaction comes to an end and the line stabilizes horizontally. It is correct to assume that the highest rate at the beginning of the experiment is due to the absence of substrate for the enzyme to work with. This means, that at the very first contact it has with the water peroxide, all enzymes start working at the same time as they are not affected by the concentration of the substrate since there is enough substrate for all the enzymes to react with. But as time passes, there is less substrate to react with and so the rate slows down. The cause of its instability is that at time 140s and 180s the reaction was shaken, so because of the energy given, the reaction fastened again. ...read more.


Conclusion: We found out experimentally that the reaction with the cow liver catalase was faster at a higher temperature, and that there was enzyme activity in both experiments, by watching how O2 was released in the measuring cylinder. Errors: - The flask was shaken only after 140s since the beginning of the experiment. - There might have been some air in the tube generating the oxygen before the experiment started. - The error for the time is quite large. This is due to the period between a person reading (or even re-reading) the values while the other one is recording the data. - Some air might have escaped back to the syringe. - The temperature inside the reaction was not actually measured, but the tap water outside it. - When putting the cylinder upside-down, some air remained in it and so made it difficult to measure well the O2 released. Improvements: - Shake the flask constantly to allow complete mixture of both reactants. - Re-do the experiment until there is no air at all in the measuring cylinder. - Be permanently watching the thermometer until the college tells you to tell him the data. ?? ?? ?? ?? Nicol�s Lamberti 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 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. Browning Enzyme

    discs as evenly as possible to attain an average amount of juice. I should try to crush the discs as much as possible, to make for juice available to measure in colorimetre. Perhaps if filtered correctly next time, the volume would be the same however if not, then I should

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

    However, although the enzyme, Catalase, occurs in the potato tissue, I did not know the exact quantity and certain discs might have more Catalase than others. This could be a major limitation in this investigation. I have tried to compensate for this, however, by taking multiple readings for each enzyme concentration so that inaccuracies are minimised once averaged.

  1. Enzyme Lab. pothesis: If liver and potato tissue are tested for the amount ...

    Massed 2g of liver tissue. 17. Measured 1 mL of 3% H2O2 and added it to the test tube. 18. Placed liver on the side of the test tube so that it was not touching the H2O2. 19. Placed the rubber stopper in the test tube and tilted the

  2. Determining the rate of action of an enzyme

    Human error Respondent: The rate of action of the Catalase The height of the detergent bubbles in the column will be measured at 30second intervals in a measuring cylinder 0.5mL Extraneous: The temperature of the reaction environment N/A N/A The humidity of the reaction environment N/A N/A The pressure of

  1. Bipedalism vs. Quadrapedalism

    Repeat steps 1-4 with books and without books for a total of 4 trials each using 2 and 4 legs. 6. Record any significant difference. Data: ~ Recorded Times in Seconds Results 2 Legs No books 2 Legs With Books 4 Legs No Books 4 Legs With Books 6

  2. Affect of temperature on enzyme peroxidase

    Since the optimum temperature of peroxidase acquired from potato ranges from 30? to 45?3, temperatures higher than 45? will decrease the rate of oxygen gas production, hence decreasing the enzyme activity. This is due to the fact that at temperatures higher than the optimum temperatures, the enzymes are denatured and

  1. How does changing the temperature of green beans affect the activity of the peroxidase ...

    We had very few outliers, with only one notable one which occurred at 80 degrees when we recorded a result of 7mL of oxygen being produces while the other results varied from 0-2mL, this would have increased our mean rate value at this temperature, potentially causing our graph to be less steep than expected.

  2. How does the concentration of hydrogen peroxide (substrate) affect the enzymatic activity of catalase ...

    Glass equipment to be handled with care to avoid glass breakage 4. Long hair should be tied back Diagram Method 1. Chop 2 carrots into small pieces and blend with 100ml of water in the blender. 2. Filter the blended carrots with filtering paper into a beaker 3.

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