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

Effect of Substrate Concentration on the Activity of Catalase.

Extracts from this document...

Introduction

Effect of Substrate Concentration on the Activity of Catalase Aim: To examine how the concentration of the substrate Hydrogen Peroxide affects the rate of reaction of the enzyme catalase. Introduction: Enzymes such as catalase are protein molecules which are found in living cells. They are used to speed up specific reactions in the cells. They are all very specific as each enzyme just performs one particular reaction. Catalase is an enzyme found in food such as potato, apples and liver. It is used for removing Hydrogen Peroxide from the cells. Hydrogen Peroxide is a poisonous by-product of metabolism. Catalase speeds up the decomposition of Hydrogen Peroxide into water and the oxygen as shown in the equation below: Hydrogen Peroxide Catalase Water + Oxygen 2H2O2 2H2O +O2 Prediction: It was predicted that as the substrate concentration increases, the rate of reaction will increase at a directly proportional rate until the solution becomes saturated with the substrate Hydrogen Peroxide. When this saturation point is reached, then adding extra substrate will make no difference. The rate steadily increases when more substrate is added because more of the active sites of the enzyme are being used which results in more reactions so the required amount of oxygen is made more quickly. Once the amount of substrate molecules added exceeds the number of active sites available then the rate of reaction will no longer increase. ...read more.

Middle

Where the substrate is in short supply (i.e. it is limiting) an increase in enzyme concentration has no effect. The enzyme concentration was varied by altering the number of equal sized discs of potato that contain the Catalase, in the reaction. The greater the number of discs, the greater the enzyme concentration. When measuring the volumes of Hydrogen Peroxide, the measurement should be the taken from a 90-degree angle to avoid parallax error. Apparatus: * Bung with delivery tube * Gas syringe barrel (20cm3) * Clamp stand * Syringe(5cm3) * 50 cm3 pH 7 buffer * Hydrogen Peroxide 50 cm3 (5-25 volume) * Knife * Beaker * Test tubes * Test tube rack * Ceramic tile * Stop clock * Safety goggles * Forceps * Ruler * Potato * Cock borer 10mm diameter Take care with the Hydrogen Peroxide. Wear safety goggles and try to get any on the skin, wash it off immediately if you do. Method: * Using the cork borer, cut a cylinder of potato tuber tissue into cm intervals using a knife and plastic ruler. Slice the cylinder into discs 1mm thick. * Place the discs into a few cm of pH 7 buffer in a beaker to keep them moist. * Assemble the apparatus shown below. * Take particular care against breakage as you insert the delivery tube into the syringe barrel. ...read more.

Conclusion

Evaluation: To enable this experiment to be completed as accurate as possible, it was repeated three times and then an average of all the results was used to plot a graph with a line of best fit. The variables for all the experiments were the same except for the concentration of Hydrogen Peroxide. However, in reality it is impossible to keep all the variables precisely the same for example: * There was a slight delay between pouring the Hydrogen Peroxide with the potato discs into the test tube of each individual experiment but as all the three steps were carried out in the same way for all the experiments, it should not make any difference to the overall result. * It is also impossible to precisely measure out the amounts of Hydrogen Peroxide and pH 7 buffer each time. As the scale on the syringe shows the volume to the nearest mm3, the volumes of the solutions were correct to the nearest mm3. There were no anomalies found in this experiment. As using catalase found in potatoes, the desired amount was hard to measure. Measuring the amount of potato wasn't difficult although the pieces could have contained different amounts of catalase compared to another piece. The results that were shown from both pieces could be negotiable. The problem of the delay between pouring in the Hydrogen Peroxide, bunging the test tube and starting the stop clock could have been limited by getting another person to start the stop clock when the Hydrogen Peroxide was poured into the tube. ...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

    Enzymes - investigate how the substrate concentration (H2O2) affects the activity of catalase on ...

    3 star(s)

    I will make sure that that the burette is straight at 90 degrees to the work surface at all times, to avoid parallax error. In addition to this other fair testing measures will be maintained throughout the experiment to limit errors in the results.

  2. An Investigation Into the Effect of Substrate Concentration On the Rate of Enzyme Activity.

    will be used to carry out the final experiment. To do this, four different concentrations of hydrogen peroxide will be made. The different concentrations of hydrogen peroxide will be placed into four different test tubes, the test tubes will then be labelled by their concentrations.

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

    * Solution was shaken before removing photographic film, the film was removed and once again the tube was shaken so that the mixture was mixed together properly, then poured equal amount of solution into each cuvette which were of the same type.

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

    the curves to be less steep, showing a sloIr rate of reaction. To analyse further the single graphs, I also expect the curves to be reaching a plateau, at which the rate has reached a constant value and no longer increases or decreases, and proceeds constantly until the reaction stops.

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

    Results Temperature of Hydrogen peroxide/ water solution ( C) First reading of the amount of gas given off (ml) Second reading of the amount of gas given off (ml) Third reading of the amount of gas given off (ml) Average of the three readings(ml) 20 10 9 8.5 9.1 25 11 11 10 10.6 30 12.5 13 15 13.5

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

    Temperature: It is possible that the temperature of the solutions may change throughout the experiment, depending on the heating of the room, weather conditions, wind from the windows etc. Constant checks, using a thermometer, are needed to make sure that the temperature of the reactants is constant right the way through the duration of the experiment.

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

    However heat energy also increases the vibration of the atoms, which make up the enzyme molecule. If the vibration becomes too violent then the chemical bonds in the enzyme break. As the vibration becomes violent and the chemical bonds break up this means that the enzyme has denatured and will change shape at a high temperature.

  2. WHAT EFFECT DOES SUBSTRATE HAVE ON THE RATE OF RESPIRATION IN SACCHAROMYCES CEREVISIAE?

    The products formed are released and the active site is free therefore it can accept another substrate molecule. The breaking of the peptide bond mentioned above is a hydrolysis reaction. The hydrolysis of a disaccharide, maltose is illustrated below. The disaccharide maltose, splits into 2 monosaccharide molecules of alpha glucose.

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