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

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The effect of Copper Sulphate concentration on Catalase activity on Hydrogen Peroxide Aim: The aim of my investigation is to explore the effects of chemical inhibitors upon the rate of reaction. The reaction I am going to focus on is the breakdown of Hydrogen Peroxide by the enzyme Catalase. Such reaction is represented by the following equation: 2H202 (aq) ?2H20 (l) + 02 (g) Hydrogen peroxide, H2O2, is a colourless, syrupy liquid that is a strong oxidising agent and, in water solution, a Iak acid. It is miscible with cold water and is soluble in alcohol and ether. Although pure hydrogen peroxide is fairly stable, it decomposes into water and oxygen when heated above about 80�C; it also decomposes in the presence of numerous catalysts, e.g., most metals, acids, or oxidisable organic materials. A small amount of stabiliser, usually acetanilide, is often added to it. Upon the bases of this information, collected from the source (www.encyclopedia.com) and a pilot experiment, which I carried out, I decided that the latter could function as a suitable substrate for the reaction I am going to be studying. Catalase is an enzyme: enzymes are biological catalysts that speed up the rate of a reaction by loIring the activation energy needed to initially break the bonds that hold the reactant molecules together. Catalases are some of the most efficient enzymes found in cells. Each catalase molecule can decompose millions of hydrogen peroxide molecules every second (200,000 catalytic events/second). Catalase is encountered in most living tissues, and it is present in nearly all the peroxisomes of nearly all aerobic cells, serving to protect the cell from the toxic effects of hydrogen peroxide by catalysing its decomposition into molecular oxygen and water. I shall describe in more detail the nature of this process: our cells are constantly supplied with oxygen. The latter is a vital molecule for our body but it has also got some dangers; one of them is that it is easily converted into reactive compounds. ...read more.


will be 35 ?C Goggles They are worn throughout the course of the experiment. To prevent harmful substances such as hydrogen peroxide and copper sulphate entering in contact with my eyes. Lab coat To be worn throughout the course of the experiment To protect my clothing from spillages and stains Copper sulphate solution 1 mole It is used as one of the reactants in our experiment. Various concentrations of it will be reacted with the other solutions. This solution contains metal ions that work as inhibitors on the catalysis reaction. Our aim is to investigate in detail the exact effect of these ions on the course of the reaction. Pipette To measure small amounts of solutions. For small amounts of solutions it is more practical and easy to use a pipette instead of a syringe. Distilled water To be introduced into the copper sulphate solutions to create different concentrations. I aim to investigate how different concentrations of copper sulphate solution affect the rate of the catalysis. I used distilled water because??? Thermometer To measure the temperature of the surroundings (beaker containing water at 35? C) To make sure that the temperature of the surroundings is not altered during the course of the Measuring Cylinder 60 ml It is filled with water and put placed upside down in the large bowl, over the delivery tube, so that the oxygen produced by the reaction is collected inside it. The tube is completely filled with water up to the top, so that as more gas is collected the level of water will go down, and the volume occupied by the oxygen is easily calculated by looking at the scale on the cylinder. Method: I shall now, describe the procedure, which I folloId to carry out the experiment: * From a fresh potato I extracted, with the use of the potato borer, several tubes of constant diameter and length (0.5 cm diameter, 5 cm length), I decided after a pilot experiment, that these measurements would give a give ...read more.


* In order to obtain a pattern of results, that would have been easier to interpret and to draw conclusions from, I could have used a wider range of inhibitor concentrations, standing at smaller intervals. E.g. 100%, 90%, , , possibly intervals of 10. In this way I could have observed the course of the reaction from a closer view in a way, and perhaps quantify the relationship of inverse proportionality betIen the variables. I could have also done more repeats, in order to obtain a more reliable average. * Now that I have explained how the equipment I used was inaccurate I will make a list of the equipment that I might have used, if available: o Open-ended graduated gas syringe o Electronically controlled water bath o Yeast instead of potato o Powdered potato if potato was the only one available Validity of conclusion: I conclude that the results obtained from my experiment are reliable enough for me to consider it successful. I have done a number of repeats, and no major dispersion has been identified. HoIver I have a major source of error: the fact that I couldn't access that water bath directly affected, in my opinion, largely my results, and it is a possible justification for my anomalous results. Not having a constant temperature for the reaction, meant that the rate of reaction varied with the days, as the temperature of the surrounding environment varied with the days. If I Ire to rank my sources of error in an descending scale, the ranking would be the following: * Inaccessibility to the water bath directly * Use of the measuring cylinder instead of gas syringe * Shaking the test tubes to mix the reactants. Overall though my results Ire reliable enough to show a pattern and to support the hypotheses that I had made, as Ill as that I have the Standard Deviation test to prove that the dispersion in my results is not major. ...read more.

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