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

The effect that potato surface area and Hydrogen Peroxide concentration have on the rate of reaction for the enzyme catalase

Extracts from this document...


Aim: My aim in this investigation is to look at the effect that potato surface area and Hydrogen Peroxide concentration have on the rate of reaction for the enzyme catalase. Preliminary Work: Before deciding on this method of testing I did preliminary work to decide which method would be most effective and provide the best results. First I tried using electronic scales to measure the weight of the potato segment and, looking at its weight at the beginning of the experiment and after ten minutes, calculate the weight loss of hydrogen peroxide. This proved ineffective because the scales were too sensitive and minor tremors could give an inaccurate result. The weight of a gas is also very low, so the results were meaningless. I would have to perform a different experiment. Background: The enzyme I will be using for this investigation is catalase. Catalase is a breaker enzyme found in potatoes that breaks down hydrogen peroxide into water and oxygen. It is the fastest working enzyme currently known. Catalase has evolved to work quickly because hydrogen peroxide is a waste product from reactions taking place within the potato cells, which builds up in the cytoplasm of the potato cell. ...read more.


Criteria Changed Criteria Kept The Same Concentration of H2O2 pH Value Temperature Potato Surface Area Weight of Potato Prediction: My prediction was that as the molarity or the concentration of hydrogen peroxide increases the rate of reaction would also increase proportionally. This was because the higher the concentration the more molecules of hydrogen peroxide there would be compared to the water in the solution. The particle theory states that the more molecules of hydrogen peroxide there are the greater the chance they will collide with the enzyme and be taken into its active site. As more enzymes arrive at the active site, more will be broken down into oxygen (and water) so at the end of ten minutes more oxygen will have accumulated in the measuring cylinder. Should the concentration reach a point at which all the active sites are being used than the reaction will level off and remain constant. I predicted that the higher the concentration of hydrogen peroxide the more oxygen would be collected in the measuring cylinder at the end of the experiment and that the control would not produce any oxygen. Results: Oxygen After 600 Seconds (ml) ...read more.


These results could be indicating that the enzyme active sites are reaching full capacity as I outline in my prediction. In order to test this I could repeat the experiment but use concentrations of 30%, 35%, 40% and 45% as well. To improve the overall reliability of the experiment I could use a gas syringe to collect the oxygen instead of a measuring cylinder, as the gas syringe would be more accurate at measuring the amount of oxygen given off, measuring the amount to 1d.p reliably. Using a computer program to measure the amount of gas in the syringe with more specialised equipment would yield a further increase in accuracy. Analysing the results for this experiment, even taking anomalies into account the reliability of the results is still good since the amount of oxygen collected in all three repeats are quite close, perhaps measuring to 1d.p with a more reliable method would reveal a closer connection. The anomalies could be caused by the rate of reaction stabilising since the active sites on the catalase enzyme may be reaching saturation point and become unable to accept more hydrogen peroxide molecules. As additional work to further my investigation into enzymes I could do similar experiments to calculate the rate of reaction for other enzymes such as amylase and protease and compare them. ...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. Marked by a teacher

    Plan: The effect of the end product, phosphate, on the enzyme phosphatase

    5 star(s)

    Put the lid back and switch on the liquidizer until all the potato pieces have turned to mashed. Then I will use the big funnel and muslin to filtrate the mashed potato and collect the liquid extracted for 15-16 cm3.

  2. Marked by a teacher

    Investigating the effects of surface area on the rate of enzyme reactions.

    4 star(s)

    and at very low temperatures the enzymes are still working, but at a very low rate. 3) Substrate concentration: When there is a low concentration of substrate, there are many active sites that are free, and this means the rate of reaction will be low.

  1. Investigating the effect of enzyme catalase concentration on hydrogen peroxide.

    The graph can be divided into three sections. The first of these sections is 2-8 potato discs along the X-axis when the number of bubbles produced on average in two minute rises from 3.5 to 19; this therefore is an increase of 1bubble every ten seconds on average.

  2. Experiment to investigate the effect of surface area on the rate of reaction.

    unable to: * Room Temperature - As we are working with enzymes, the temperature at which the enzymes work. This could be controlled by air conditioning, monitoring the change in temperature, s they do in hospital theatres. * Safety points.

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

    This would certainly lead to imprecise and unreliable results. KEY FACTORS I know from my work and notes that there are 5 factors that affect enzymic rate of reaction: temperature, pH, enzyme concentration, substrate concentration, and pressure. To obtain valid and accurate results, it is very important that only one of these is varied; the enzyme concentration used in the experiment.

  2. Osmosis is defined as 'the movement of water molecules from an area of high ...

    4 1.42 1.36 -0.06 -4.2253 5 1.66 1.51 -0.15 -9.0361 6 1.6 1.52 -0.08 -5 average 1.645 1.51166 -0.1333 -7.9764 0.75m concentration mass before (g) mass after (g) change in mass (g) % change in mass 1 1.64 1.36 -0.28 -17.073 2 1.49 1.34 -0.15 -10.067 3 1.87 1.74 -0.13

  1. Investigating an enzyme-catalyzed reaction

    This makes my conclusion less reliable because the results are not very consistent and are widely spread out. However you can still see that the line on my graph has an upwards trail which is what I expected before I started the experiment.

  2. An investigation into the effect of a substrate concentration on the reaction rate of ...

    When there is a high enzyme concentration, there are more active sites available for substrate to use. This means there is a higher chance and more opportunities for a substrate colliding into an available active site. The more collisions with the active site, the faster the reaction.

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