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

for this experiment my main aim is to investigate the effect of temperature on enzyme activity

Extracts from this document...

Introduction

BIOLOGY COURSEWORK My Aim: for this experiment my main aim is to investigate the effect of temperature on enzyme activity. In this case Catalase is my enzyme and Hydrogen peroxide is my substrate, I will be reacting both of them at different temperatures. Introduction Catalase is an enzyme found in tissues of most living things. It promotes the conversion of hydrogen peroxide, a powerful and potentially harmful oxidizing agent, to water and molecular oxygen. 2H2O2 to 2H2O + O2 Catalase also uses hydrogen peroxide to oxidize toxins including phenols, formic acid, formaldehyde and alcohols. H2O2 + RH2 to 2H2O + R What does Catalase look like? Each molecule of Catalase is a tetramer of four polypeptide chains. Each chain is composed of more than 500 amino acids. Located within this tetramer are four porphyrin haem groups that are very much like the familiar haemoglobins, cytochromes, chlorophylls and nitrogen-fixing enzymes in legumes. The haem group is responsible for catalase's enzymatic activity. Catalase has one of the highest turnover rates for all enzymes: one molecule of Catalase can convert 6 million molecules of hydrogen peroxide to water and oxygen each minute. Enzymes (protein molecules) are biological catalysts that help speed up the rate of chemical reaction and they remain unchanged after reaction. Almost every metabolic reaction that takes place within a living organism is catalysed by an enzyme. It is also important that we know the shape of enzymes, they are globular proteins and like all other globular proteins, enzymes take 3-D shape with a hydropholic R groups on the outside of the molecule ensuring that they are soluble. It is also important to recognise one of the main feature enzymes possess which is their Active Site. This active site helps enzymes catalyse reaction. It is usually a depression to which another molecule or molecules can bind. The molecules that bind with the active site of an enzyme are called Substrate. ...read more.

Middle

Below are the apparatus that I will be using for this experiment and their uses. Rubber gloves: to ensure hands are kept clean when handling the lamb liver and also insures germs and bacteria's are not transferred from one place to another Safety glasses: this will keep the eyes safely guarded from the hydrogen peroxide incase you might come in to contact with the hydrogen peroxide around that area. Vaseline: this will lubricate the inside of the syringe so the syringe can pull in or out with ease so the wont be any jamming of any sort during the experiment. Large beaker: this will act as a container for the water (which would be at a certain temperature) and the conical flask. It will also allow us to measure how much water we add each time to keep the experiment fair and accurate. Small beaker: this will hold the hydrogen peroxide to ensure easy access during the experiment. It will also allow me to easily use the pipette during the measurement of the hydrogen peroxide. Pipette: this allows me to accurately measure the amount of hydrogen peroxide required (0.8cm cubed) for the experiment. Syringe: this allows me to measure the amount of oxygen produced. It will also allow me to tell the amount of oxygen produced at the 5 seconds intervals. Retort stand: this will hold the syringe in place so I can take down accurate readings during the experiment. Stopwatch: I will be using this to time my experiment. This will also be used to tell me when I need to take down my readings of the 5 second interval. Hydrogen peroxide: will use it with the liver (source of Catalase) to cause a reaction and allow oxygen to be released which I will measure. Lamb liver: this will be my source of Catalase which I will add with the hydrogen peroxide and measure its reaction rate at different temperatures. Knife: this will allow me to cut up precise amounts of liver (0.3grams). ...read more.

Conclusion

A more accurate method should be used to collect oxygen displaced (if any) in order to reduce unnecessary lose of oxygen, and if there aren't any one should be as fast as possible in placing the cork on top of the conical flask, as this will prevent unnecessary lose of oxygen (iv) Try as much as possible to use the same equipments, such as the syringe so that measurements will be less affected, you can make sure you use the same equipment by labeling the equipment used (v) The experiment should be repeated more and a wider range of temperatures should be used to give a more broad analysis of the experiment, so that my results are better and a more accurate average is obtained, even though I repeated the experiments three times, more repetition of the experiment is more helpful in obtaining a more reliable and accurate initial rate of reaction(vi) Try as much as possible to do a particular temperature on the same day as both the liver and the catalase will still be in the same condition for all temperatures, this will help limit the chances of getting anomalies. Overall my experimental evidence was a reliable one, despite the effect of the errors and limitations because it supported my hypothesis and the basic knowledge about enzyme. It showed the trend of increased rate of reaction as temperatures increases up to optimum temperature, and also how rate of reaction decreases as temperatures go past optimum temperature, although the experiment will be more successful if I did this experiment again and made these changes mentioned above to it. Finally all the improvements mentioned above are a good way of increasing the reliability of experimental evidence and also minimizing significant sources of errors, as too many uncertainties in evidence may affect conclusion drawing. The presence of this limitations and errors are quite significant because it reflected on the results table. ...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

    The aim of this activity is to investigate the effect of a reduction in ...

    3 star(s)

    Tap the bases of the test tubes to mix the solutions. 5. Measure the time needed for the milk to turn clear in each test tube. Variables * The independent variable within this experiment is the concentration of the trypsin.

  2. Marked by a teacher

    Liver and Hydrogen Peroxide experiment

    3 star(s)

    Therefore: * Goggles and safety clothing should be worn. * Gloves worn * If spilt clean up * If spilt on clothing change clothing * And the knife When experiment is redone: Pestle and mortar need to be cleaned out because more catalase will speed up the reaction.

  1. An experiment to investigate the effect of temperature on the action of the enzyme ...

    It was difficult to see when the colour had changed and I was not sure whether the transition had been fully completed. In the actual experiment, the control had phenolphthalein in it, so all we had was to compare it with a purple solution.

  2. Does ethanol causes greater inhibition of pig liver catalase than of yeast catalase

    made and the more oxygen is made the faster the bead will float back up to the surface. I will have to do pilot experiments to keep the reaction to a good speed as if it is to fast the bead may just float as soon as there put in,

  1. The effect of enzyme concentrations on the reaction time of Urease active meal.

    * Carry out my experiment in a ventilated fume cupboard as the chemicals I will be using give off irritating vapours. The fume cupboard will ensure that all toxic gases escape successfully. * Make sure that there are no leading wires from the pipes, the electronic cables from the electronic balance.

  2. Investigating the effect of temperature on the activity of free and immobilised enzymes.

    * A bung was then placed on conical flask and inverted several times to ensure that the enzyme solution and the distilled water are well mixed. Immobilised enzymes method * The required temperature was set on the water bath and the test tube rack was placed in the water bath.

  1. The effect of Copper Sulphate concentration on Catalase activity on Hydrogen Peroxide.

    Irreversible inhibition of enzymes also occurs, due to the presence of a poison. For example, penicillin cause the death of bacteria due to irreversible inhibition of an enzyme needed to form the bacterial cell wall. In humans, hydrogen cyanide irreversibly binds to a very important enzyme (cytochrome oxidase)

  2. WHAT EFFECT DOES SUBSTRATE HAVE ON THE RATE OF RESPIRATION IN SACCHAROMYCES CEREVISIAE?

    The final substrate that I am testing is lactose. This substrate is a disaccharide made from one molecule of glucose and one molecule of galactose. It also requires a digestive enzyme to hydrolyse it and break it down before it can enter the cytoplasm of the saccharomyces cerevisiae cells by facilitated diffusion.

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