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

The Effect of Substrate Concentration on the activity on the Enzyme, Catalase.

Extracts from this document...


The Effect of Substrate Concentration on the activity on the Enzyme, Catalase. Modifications When carrying out the experiment several activities stood out as needing improvements to produce valid results. Altogether four alterations have been made these are: 1. In the planning the stated method for increasing concentrations of hydrogen peroxide was to increase the molarity. However as different molarities of hydrogen peroxide were not available instead the concentration was increased adding more of hydrogen peroxide for each experiment. This method also increases the amount of substrate (hydrogen peroxide) molecules in the solution. Therefore has the same effect. The new concentrations used were: 2ml H2O2, 4ml H2O2, 6ml H2O2, 8ml H2O2 and 10ml H2O2. 2. Due to the lack of equipment to start the reaction the syringe contents (substrate) had to be pushed into the boiling tube and then the bung replaced. Rather than pushed through a hole with a bung in. This was a less precise option but unavoidable. 3. In practice a biurette was not used. The purpose of a biurette was to produce very accurate results. This is not necessary however because a measuring cylinder would suffice. A 10 ml measuring cylinder was used instead, which gave the results to 0.1 ml accuracy. This is accurate enough to plot a graph with. ...read more.


This type of reaction where a molecule is broken down into smaller components is called an anabolic reaction. On the first graph the reaction steadily increases until it reaches 6ml concentration and 6.1 of oxygen gas has been given off. Therefore as the concentration of hydrogen peroxide increases so does the rate of reaction. As more enzymes active sites are being occupied more oxygen gas is being produced. Until another factor such as enzyme concentration restricts the rate of reaction. This is because once all the enzymes active sites are occupied (said to be saturated) the enzymes cannot work any faster. The maximum numbers of active sites are being used. Therefore the time to enter and then leave the active site becomes a limiting factor. Any extra substrate molecules have to wait for an active site to be empty. Thus at the beginning of the graph we can see that the enzyme is in excess and therefore as more substrate is added the faster the reaction can go. When the graph levels off the substrate is in excess and therefore the enzyme is limiting. Therefore this experiment reflects the concentration theory. According to my results the fastest reaction was at 6 ml of hydrogen peroxide however the result might have been different had I used more concentrations for example every 0.5 ml intervals instead of 2ml intervals. ...read more.


Gas is lost before the bung is replaced. The results will be less than expected because gas will have been lost. A smaller amount of oxygen produced. 3) Impossible to start stopwatch and place hydrogen peroxide in the boiling tube simultaneously. Some experiments will have more time to react. It means that results are going to be slightly out from what they should be. If they have more time to react then the gas given off is going to be bigger than it should be. Therefore the results are not going to form the correct curve on the graph. 4) Large gas bubbles, which collect at the top of the measuring cylinder, cannot be included. E.g. These gas bubbles cannot be included in the table of measurements. Also if the tube is shaken then even more gas is released into the measuring cylinder (not a fair test). The results will be slightly less. Depending on how often this error occurs, this could alter the results slightly. 5) Pushing the bung into the boiling tube pushes air into the delivery tube. Extra gas can be incorporated into the experiment. Depending on how far in the bung is pushed some tubes will have extra air compared to others. The experiments will have more gas. However the measurements will be wrong. There will be a higher rate of reaction. 01/05/2007 Maryanne Parker 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 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

    effects of substrate concentration on the activity of the enzyme catalase.

    4 star(s)

    So a faster reaction and faster substrate being used up. "My hypothesis is that the higher the substrate concentration the higher the collision rate with substrate enzyme particles, so the faster the substrate would be used up." I believe this because of the collision theory, which states that the higher

  2. Marked by a teacher

    To investigate the effect of substrate concentration on Catalase Activity.

    3 star(s)

    The borer drills a log circular rod which you can cut up into much smaller pieces for your use. Method The potato will be placed onto a Tile and a borer will be used to obtain a cylinder of potato.

  1. To investigate the effect of enzyme concentration on the activity of catalase in potato ...

    A way of improving this error is to put a protractor or any thing with 90o angle and cut straight down to ensure the ends are straight. Another error is in the inconsistency of the collection of the bubbles i.e.

  2. An investigation into the effect of substrate concentration on the activity of the enzyme ...

    Analysis From the results obtained from the experiments, a line graph can be drawn up as the one on the following page. Information can be plotted to clearly represent data in a more comprehensible form. Patterns and Trends Throughout the experiments, it was clear to a great extent that as

  1. Investigate the effect of enzyme concentration on the activity of catalase in potato tuber ...

    Adding increase vols. of the mash instead of increase potato sticks as a measure of enzyme concentration. Also it will ensure a fairer test. Maybe having a source of catalase from yeast would have been much easier to use and handle.

  2. Investigate the effect of temperature on the activity of catalase (from potato)

    thermometers etc, the readings are taken with the graduated markings at eye level, so as to minimise the risk of inaccurate readings. 4. All boiling tubes etc. must be washed thoroughly with water after their use, so as to minimise the chance of contamination.

  1. Free essay

    Investigation Into the Effect of Substrate Concentration On The Activity Of An Enzyme

    Enzymes work best at a 7 neutral. * Concentration of Substrate: If the Substrate is in excess then this means that every Enzyme will join to one of the substrate's this also means that there is more of a chance of an enzyme and substrate colliding so the reaction will occur faster.

  2. Investigating the Effect of Substrate Concentration on Catalase

    and therefore the active sites work at their optimum speed and the rate of reaction reaches its maximum. After this point is reached, the rate of reaction levels off as the substrate will be in excess and the active site cannot work any faster.

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