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

How Does Changing the Substrate Concentration Affect the Rate of an Enzyme Controlled Reaction?

Extracts from this document...

Introduction

How Does Changing the Substrate Concentration Affect the Rate of an Enzyme Controlled Reaction? Aim The aim of my investigation is to find out how changing the substrate concentration affects the rate of an enzyme controlled reaction. The enzyme is catalase & the substrate is hydrogen peroxide. The catalase breaks down the hydrogen peroxide and the end result is water and oxygen. I will measure the amount of oxygen gas produced. Prediction I think that the higher the concentration of hydrogen peroxide is, the rate of reaction will be quicker & the most gas will be produced with the highest concentration. Explanation Enzymes and substrates have complimentary shapes. When a substrate collides with an enzymes active site, (Lock and Key) bonds within the substrate are broken & the products are released. If a beaker contains a low substrate concentration, this means there are few substrate molecules present. The reaction will be slow; this is because there is less chance of a collision between the enzyme & the substrate, this means that fewer products will be released. Whereas if another beaker has a high concentration of substrate, the reaction rate will be much more vigorous, this means more collisions and more products being released. ...read more.

Middle

Step 4-Get a boiling tube and measure out 1g of yeast into it, get a clamp stand. Step 5-Place the boiling tube containing the yeast into the clamp stand so it is just above the water in the trough. Step 6-Get another test tube or boiling tube and place a 20% concentration of hydrogen peroxide into it. Use the guide on the pipette to measure out 4ml. Step 7-Get a delivery tube & bung, place the transparent 'L' shaped end underneath the lip of the measuring cylinder in the trough, so it is just inside the cylinder. Step 8-Get a stopwatch. Pour the hydrogen peroxide into the tube with the yeast in it, and then very quickly place the bung securely into the tube. Once the bung is securely in place, start the stopwatch. Once it has reached 10 seconds, take the first reading of how much gas has been produced, do this again when it reaches 20 seconds and take a final reading at 30 seconds. Step 9-Once you've completed this for the 20% concentration, repeat it with concentrations of 15%, 10%, 5%, and 2.5% concentrations. Repeat each concentration, including the 20% 3 times in total. Results Table Amount of gas (Cm3) ...read more.

Conclusion

I had two anomalous results. For 10 seconds, the 2.5% concentration of hydrogen peroxide collected more gas than the 5% at 10 seconds. This lowers the reliability of my results. Something that could have affected the results is the equipment. The first delivery tube we used got clogged up so we had to change it, this new tube could have been wider or shorter than the first one. I carried out repeats then took my averages. Another thing that could have affected my results is the people. Something that could have affected the results is the measuring of the yeast and hydrogen peroxide, towards the end of the experiment we were running out of time, and may have taken wrong amounts of yeast and substrate which could be why there are anomalous results. I feel like my results aren't as reliable as they could be, if we did the experiment again and had more time I think we would have more reliable results because we wouldn't have messed up the amounts of yeast and hydrogen peroxide. If there were more concentrations I would be able to explain more about the rates of reaction because if there was a 25% or a 50% concentration I would have a more reliable set of results because I would have repeated it 3 times and had more results to work with. ...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. Investigating the Effect of Enzyme Concentration on Rate of Reaction.

    would be much harder (in discs, the enzyme available to react is only on the surface of the potato piece). I feel that having the enzyme in a solution in a beaker keeps the enzyme together at a constant concentration much better.

  2. Investigating an enzyme-catalyzed reaction

    Water 4- 5ml Hydrogen Peroxide, 2ml Yeast Solution, 3ml Distilled Water 5- 5ml Hydrogen Peroxide, 1ml Yeast solution, 4ml Distilled water 13) After you have the correct measurements you pour the yeast solution into the reaction tube, making sure that you poured it all in.

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

    * Surface area of yeast * Temperature of hydrogen peroxide * Temperature of room * Concentration of hydrogen peroxide (Dependant variable) Substrate concentration A higher substrate concentration means there is a greater number of substrate molecules. Therefore, there is a higher probability that the molecules will collide and so the reaction will occur at a faster rate.

  2. Investigating the Effect of Substrate Concentration on Catalase

    therefore I shall use pH7. The recording intervals of 15 seconds is quite a good length of time as it enabled enough oxygen to be produced for a clear graph to be plotted. The trials will last for 180s rather than 120s because some of the concentrations that will be

  1. 'The effect of changing the concentration of the substrate hydrogen peroxide on the rate ...

    substrate the rate of activity should increase too because there will be more substrate molecules which can react will enzymes, but only up to a certain point, when all the enzyme has being used, then the rate of activity should stay at the same rate.

  2. An Investigation into how the varying concentration of a substrate affects the rate of ...

    the active site of the enzyme becomes saturated so as soon as one substrate molecule is turned into products, the enzyme is immediately taken up by another substrate molecule. Therefore the enzyme is working as hard as it can so the rate of reaction can't increase anymore.

  1. Investigation into the effect on the rate of reaction of the breakdown of hydrogen ...

    They bond so the water hating hydrophobic R-groups are at the centre of the protein, away from their watery surroundings. The hydrophilic R-group exterior of the protein means that they are soluble in water and can work in aqueous solution in living cells.

  2. Does changing the concentration of enzymes affect the rate of an enzyme- controlled reaction?

    I then measured 20ml of hydrogen peroxide using a measuring cylinder and then I poured it into the boiling tube. Next using a ruler I took a slice of potato and I cut 5 equal chunks measuring each chunk to be 2cm in length.

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