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

The Effect of pH on the activity of catalase.

Extracts from this document...

Introduction

Dereje Mengiostu Work partners Sana & Derek Date3rd Nov The Effect of pH on the activity of catalase Introduction Enzymes are sensitive to pH i.e. they have a specific pH in which they can work best. Some work best in acidic medium while others work best in basic medium - yet others are more active in neutral medium. In this experiment we tried to investigate the effect of pH on the activity of catalase. Catalase is a respiratory enzyme that breaks down H2O2 which is produced by cellular respiration as a bi product. Catalase breaks down it in to water and oxygen gas. As every enzyme the activity of catalase is highly influenced by variation of pH. From theory we know that it works best at the pH value of 9. What is the ideal pH for catalase to work best? Apparatuses and chemicals used in the experiment * HCl acid to increase acidity of the substrate * NaOH to give the substrate a basic nature * Diluted H2O2 as a substrate to be acted upon by catalyse * Blundered liver as a source ...read more.

Middle

12drops of NaOH 9.3 77 101 89 4. 3 drops of HCl +9 drops of H2O 1.9 5 6 5.5 5. 3 drops of NaOH + 9 drops of H2O 8.6 125 127 126 6. 9 drops of HCl +3 drops of H2O 1.7 3 3 3 Discussion In this particular experiment we have used the same amount of H2O2 (20 ml) and blundered liver (0.5 ml) that contains naturally made catalase produced by liver cells through out the experiment but we had to change the pH level by varying number of drops of NaOH base, HCl acid & H2O in each trial as indicated above in the table of results. Though I do not dare to say our experiment is quite precise as it should be we could get a result which is very close to the theoretical ideal pH for catalase. We could prove that the activity of catalase is highest around the pH 9. From our 2nd trial we could get 121.5 cm3 of gas in average at the pH value of 9. ...read more.

Conclusion

The gas syringe was not big enough to hold the gas produced in some cases and we had to open the baker to let out the gas from the gas syringe to make it ready to measure the remaining gas produced from the reaction. This time some amount of gas has escaped. We have used 0.5 cm3 of blundered liver but we could use even smaller amount of liver to get more accurate result since we could get lesser amount of gas that could be measured easily. The problem is the uncertainty of the syringe we have used is high and it is more difficult to measure very small amount of the blundered liver with it accurately but we could have overcome this problem if we had used a syringe with lesser uncertainty or we had use bigger gas syringe if there was. I think if we had better pH measuring device or universal indicator we could get more accurate result. If we could use burette or pipette to measure the volume of H2O2 than using measuring cylinder we could get better result since these two apparatuses have lesser uncertainty. ...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. Free essay

    Investigating the effect of PH on the activity of the enzyme catalase.

    After point B, the reaction rate remains flat because the increase amounts of substrate must wait before they can fit with their enzyme. There are two theories on enzyme function - * Lock and key - the shape, structure and charge of the active site in the enzyme is complementary

  2. Investigating the effect of pH on the activity of an enzyme.

    The absorbency for each pH in all 3 experiments will be averaged out and the average results will be plotted on the graph. The average will be worked out for each pH by adding the absorbency of that specific pH from all 3 tables and dividing it by 3, as there are three set of results.

  1. The effect of pH on the activity of catalase

    The delivery tube was then placed under the burette, 1cm� of hydrogen peroxide was then measured in to a syringe and the syringe was connected to the test tube. Hydrogen peroxide was injected into the test tube (Injecting hydrogen peroxide into the test tube before positioning it under the head

  2. Investigating the Effect of pH on Enzymes

    blue light from passing through simply by increasing the severity of the precipitate but the colorimeter would be likely to read zero as some of the light may be scattered and not go straight through the solution so anomalies may be produced.

  1. Investigating the Catalase Activity in Calf and Ox Liver

    Whereas the ox liver, being older, would have been through more years of working, and may have had infections, which would affect the cells in the liver, ultimately affecting the catalase levels inside them. Controlling Variables It is important to control as many variables as possible in order to make the results reliable.

  2. An experiment to see the effect of pH on the activity of Catalase

    that experiment another 2 more time * Do the other pH solutions Weight of the Potato (g) Volume of pH Trial 1 - time taken for the gas to reach 10cm3 (s) Trial 2 Trial 3 Average 5 4.4 32.73 35.04 33.96 79.09 5 6.5 48.11 29.84 36.45 90.1 5

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