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

To investigate the effect of temperature on the breakdown of starch by amylase, and to find the optimum temperature for the reaction.

Extracts from this document...

Introduction

Aim: To investigate the effect of temperature on the breakdown of starch by amylase, and to find the optimum temperature for the reaction. Research: Enzymes are proteins that control vital biological processes. They often act as biological catalysts. They are made in cells. A catalyst is a chemical substance which speeds up a reaction but does not get used up during it. One enzyme molecule may be used several times over. If starch is mixed with water it will break down very slowly into sugar, taking several years, however, in your saliva there is an enzyme called amylase which can break down starch to sugar in minutes or seconds. A rise in temperature increases the rate of most chemical reactions and a fall in temperature will slow them down. In many cases a rise in 10� C will double the rate of reaction in a cell. This is particle theory. I am going to investigate the temperature at which reactions occur. An increase in temperature will result in a n increase in kinetic energy. Since the kinetic energy increases , the velocity of particles will also increase. Since the speed of particles increases, they should collide more often and therefore the speed of reaction increases. The particles will also have more energy thereby speeding up the reaction even more. ...read more.

Middle

to 40� C using a measuring cylinder measure 10ml of starch from the same solution each time Pour 10ml of starch into one test tube Pour 5ml of amylase into another test tube Put the test tubes into the water bath Put a thermometer into the starch solution Put 2 drops of iodine into each part of the spotting tile When the temperature becomes constant mix the amylase with the starch and start the stop clock at the same time stir twice with a stirring rod for equal agitation stir the mixture twice with the glass stirring rod Every 30seconds remove a small portion of the solution and put into a spotting tile dimple with iodine in Record the time that the solution doesn't change the colour of the iodine Repeat this at a range of different temperatures use ice to reach a lower temperatures change the temperature of the water bath Repeat each temperature twice to get more accurate results Results temperature 14� C Time in minutes colour 1st experiment colour 2nd experiment 0 black black 0.30 black black 1 black black 1.30 black black 2 black black 2.30 black black 3 black black 3.30 black black 4 black black 4.30 black black 5 black black 5.30 black black 6 black black 6.30 black black 7 black black 7.30 black black 8 black black 8.30 black black 9 black black 9.30 black black 10 ...read more.

Conclusion

The proteins structure unravels, which changes the shape of the molecule, and exposes the inner cells of the protein to the killing temperature. The gradient shows that the enzyme is not working as efficiently as it could and therefore needs a greater amount of time to breakdown the starch. This supports my prediction that amylase works best at temperatures slightly below 40� C. My graph showing the rate of reaction between the starch and the amylase shows that as the temperature increases to 40� C the rate of reaction also increases and that as the temperature increases above 40� C the rate of reaction will decrease rapidly. The peak in the rate of reaction is 37� C which is the best temperature for efficient use of amylase. The reason for the decrease in rate of reaction after 37� C is the enzyme is damaged. Evaluation My results proved my prediction to be correct. The breakdown of starch is quicker as the temperature increases until the optimum temperature after which it begins to slow down. I think my results were sufficient to support a firm conclusion, but if I had the chance to investigate further the effect of temperature on the breakdown of starch I would take more results focusing on the higher temperatures and try to pinpoint the optimum temperature. ...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 Patterns of Behaviour 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 Patterns of Behaviour essays

  1. Rates of Reaction - The Iodine Clock

    the presence of oxygen), it is therefore necessary to use freshly made KI solution. Fresh distilled water should also be available in wash bottles and as a large quantity in a tank. The starch solution should be kept in a fridge as it can provide an excellent medium for bacterial growth.

  2. The Iodine Clock Investigation

    This procedure was again repeated another four times, except in the second conical flask was placed a different concentration of H2O2, it contained: - 18ml H2O2 - 2ml distilled water This gave an overall concentration 1.8 Vol. of H2O2. This method was repeated another eight times, and each time the

  1. The effect of enzyme concentration on the rate of amylase and starch reaction.

    After 4 1/2 minutes Light Brown After 5 minutes Very light brown I have spotted many errors for example the reaction time was 30 seconds and reaction to finish within these 30 seconds. Also the volumes of solutions were so small that it was different to make any logical judgement, so I decided to have a more accurate method.

  2. Investigating the effect of enzyme concentration on the hydrolysis of starch with amylase.

    Aqueous solutions of amylopectin have high viscosity, clarity, stability, and resistance to gelling. It binds weakly with iodine and the complex typically gives a red/brown colour. Hydrolysis is the chemical process, which breaks the covalent bonds, that results in the decomposition of molecules into two by adding water.

  1. THE EFFECT OF BILE SALT ON THE ACTION OF THE ENZYME LIPASE

    This was the only device I was provided therefore I had to settle for it. It gave me the level of pH throughout the 300 seconds. However, on many occasions it failed to work. pH indicator Used to ensure the pH of the reactants in the solution.

  2. The Effect of Catalase in the Breakdown of Hydrogen Peroxide

    From this I conclude that the unpeeled potato is better during a reaction, than the peeled potato. This is due to the fast speed that the unpeeled potato has in comparison. The time to the volume of percentage ratio is constant in both graphs, as they both increase in proportion to each other.

  1. How temperature affects the rate at which bread dough rises and find out the ...

    They are biological catalyst and at the optimum temperature they work the most and with the maximum energy resulting in the highest numbers of collisions. Above this temperature they get denatured. Enzymes have got an active site in which the molecule of substrate fits and the product is formed.

  2. Activity of Diastase On Starch

    ( ph and temperature kept constant) ROUGH TRIALS The first experiment I carried out was by using 0.5% diastase and 0.5% starch solution. I wasn't able to get any reasonable titration reading because the glucose concentration was very low. The experiment was then carried out using 0.5% starch but 2% diastase solution.

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