• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. 14
  15. 15
  16. 16
  17. 17
  18. 18
  19. 19
  20. 20
  21. 21
  22. 22
  23. 23
  24. 24
  25. 25
  26. 26
  27. 27
  28. 28

'Investigating how temperature affects the rate action of the amylase enzyme on starch.'

Extracts from this document...


Aim: 'Investigating how temperature affects the rate action of the amylase enzyme on starch.' Background Reading Before conduction of both preliminary and the official investigations, I did research on enzymes, their structures and properties both during school and at home dependently using the internet, varies software and books (http://www.bbc.co.uk/revision / Encarta encyclopaedia / School Biology book). This Investigation should hopefully reinforce my understanding of enzymes and particularly the Amylase Enzyme. I have decided to express the knowledge not in this section but throughout this essay in major areas such as the prediction. Hypothesis: I hypothesise; using my scientific knowledge of enzymes from the essential background reading that increasing the temperature will increase the rate of reaction between the enzyme and the substrate accordingly. However, I am aware that the temperature can only be increased or decreased to a certain point before the reaction corrupts as the enzyme will cease to function. I believe that this will occur at above 45�C i.e. optimum temperature. Prediction: (Theory part of this applies to both the Preliminary and Official Experiment) The focal factor which has been assigned to this investigation is temperature. This Investigation will look at how the temperature affects the rate at which a bacterial amylase enzyme works upon a starch solution. Enzymes are a chain of amino acid polymers and are produced in living cells. They often act as biological catalysts and so catalyse (speed up) a reaction (a catalyst is a chemical substance which speeds up a reaction but does not get used up during it). For example, if starch is mixed with water it will break down very slowly into maltose, taking several years, however, in your saliva there is an enzyme called amylase which can break down starch to glucose in minutes or seconds. So as can be seen, water alone can react with the starch and digest it. In fact the majority of chemical reactions in the body require water. ...read more.


The Optimum Temperature is the temperature where the amylase functions most rapidly. My Prediction of 45�C for the optimum temperature was due to my knowledge of enzyme and particularly the amylase enzyme. In school and dependably elsewhere I learned that most enzyme function between 30-50�C and denature at about 60-70�C. Though I did not realise that a BACTERIAL amylase enzyme acts differently to the amylase enzyme present in the human body. And so I wasn't aware that it would have a different optimum temperature. Beyond the temperature of 75�C I did not achieve correct results of which I gave the possible reason in the evaluation. At a temperature of 80�C - 90�C my results show a time of 0s, simply meaning that the enzyme must be denatured (ceased to function) (the brown iodine turns blue/black at the start of testing and does not turn the iodine brown). I do know that this is not correct as an enzyme apparently does not denature that fast i.e. 5�C above the optimum temperature. An enzyme goes through a series of changing before it is completely denatured. The structure of its active site jostles and reforms and gradually reaches a point where its active site has changed so much that the 'key and lock theory' does not apply i.e. the substrate 'key' no longer fits into the structure of the active site 'lock'. I have made a graph showing the rate of reaction in the experiment (this is only done for the correct temperatures between 45�C-75�C. The remaining temperatures between 80�C-90�C are incorrect and so I have not included them in. The rate of reaction graph is simply done as a 1/Time graph. 1/Time Results: (Answers taken to four decimal places) 1/Time Rate Results 45 0.0019 50 0.0029 55 0.0034 60 0.0038 65 0.0050 70 0.0059 75 0.0010 Conclusion: I stated in my prediction the following: "Increasing the temperature will increase the rate of reaction between the enzyme and the substrate accordingly. ...read more.


The preliminary results are very faulty as they show that the enzyme is denatured straight after the optimum temperature-only a temperature of 80�C (5�C up, and so is very unlikely). Successfully my conclusion does agree with my prediction and theoretical prediction (can be found in the preliminary section). Evaluating: On the whole, I feel that my official investigation worked out well. My method gave results that were reliable and so could always be counted on to be correct this is because I achieved accurate results by choosing particular apparatus such as the essential water bath. I choose to use the water bath because of its accuracy and that it rules out the possibility of human error. The mistakes which I learned from my preliminary experiment led my to me to make the decision that I must improve my technique by using a very accurate piece of apparatus of which I think I have made an intelligent choice. I am sure that my experiment would not have succeeded if I was to repeat the experiment simply using beakers of water and then 'trying' to maintain that constant temperature. Most things in my investigation turned out the way I predicted. Also nothing dangerous or disastrous occurred because I carried out my investigation according to my safety procedures. All of my results seemed to fit with the main pattern as the comparisons of the graphs show. The graph has a similar shape and all the points fit well. I also felt that I had enough correct results to show a conclusion as the results match with my prediction and my background reading. ==> This successful experiment was due to recognising the mistakes in the preliminary experiment, such as the way the method was conducted, the use of some inappropriate apparatus and lack of concentration. I changed all these, and successfully obtained accurate results of which I am pleased about. [Note: can I please be awarded a mark out of 8-8-8-6 i.e. planning-obtaining evidence-analysis and conclusion-evaluation] Thanks :) ?? ?? ?? ?? Maytham Aomran Page ___ Practical Investigation 1 19/11/2001 Amylase Enzyme Investigating Enzymes ...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

    How does the pH affect the activity of amylase

    3 star(s)

    If inhaled, rinse mouth and throat thoroughly, and drink plenty of water. In most cases, this treatment will prove sufficient, but you should not be careless. Potassium Iodide The Iodide is very toxic if swallowed Iodine may be absorbed through the skin.

  2. Marked by a teacher

    Beetroot Practical Write up

    3 star(s)

    with water, or by the reduction of ethanal in the presence of a catalyst, and is widely used as a solvent. Ethanol is used as a raw material in the manufacture of ether, choral, and iodoform. It can also be added to petrol, where it improves the performance of the engine.

  1. The Effect Of Temperature On The Action Of Salivary Amylase

    Iodine Dark Blue 4 Water path 800C 5 min Iodine No change Equipment: * Starch solution * Iodine solution * Beaker * Test tubes (including clamps) * Measuring cylinder * Stop watch * Water path (370C and 800C) * Fridge * Pipette * Thermometer Method: 1)

  2. How the concentration of amylase effects the digestion of the starch.

    Step 7- Plot a graph to show the results. Analyze all the information to create a conclusion!!! REVISED METHOD Due to a shortage of apparatus I had to make a change in the way the experiment was carried out. Instead of using 13 test tubes at the same time I used only two.

  1. Investigation of the effect of adding different concentrations of NaCl to an enzyme-substrate (amylase-starch) ...

    Label these test tubes with the respective concentration: Amount of NaCl Amount of distilled water to be added Consentration of NaCl solution produced (cm�) 0.0 1.0 0.0 1.0 0.0 1.0 0.8 0.2 0.8 0.6 0.4 0.6 0.4 0.6 0.4 0.2 0.8 0.2 9.

  2. The Effect of Starch Solution on the Activity of Amylase

    What I found from this graph is that as the achromatic point increased, the rate of reaction decreased, and also that the reaction was highest for the undiluted concentration, which also had the also had the lowest achromatic point. Conclusion: My conclusion is that an increase in enzyme concentration increases the rate of reaction and the activity of the amylase.

  1. Investigating the effect of temperature on the enzyme amylase.

    I need to be careful when handling glass not to break the test tubes or the glass pipettes so I do not cut myself. It is very important that health and safety is observed considering the saliva. Test tubes should be labelled so they are not mixed up and picked up by accident.

  2. An investigation to find the best temperature for the enzyme Amylase

    Stop watches Splints 250ml beaker H20 bath set at 37�C 10ml measuring cylinder Iodine solution Thermometer Method: 1. Place 2cm� starch in a test tube Half fill beaker with water of your chosen temperature. Place test tube in it. Place thermometer in at the same time.

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