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Investigation into how changing the potato catalase enzyme concentration affects the rate of reaction.

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Investigation into how changing the potato catalase enzyme concentration affects the rate of reaction. An enzyme is a biological catalyst, which controls all the chemical reactions inside the cell. A catalyst is a substance, which alters the rate of reaction. This catalase is found in the potato. The potato catalase enzyme Hydrogen Peroxide Water Oxygen 2H2 O2 2H2 O + O2 Diagram Plan I am going to change the enzyme concentration by using several different numbers of potato cylinders. Going up in centimetre pieces, I will find the range of pieces needed and how many readings are needed from doing preliminary experiments. I am going to measure how much oxygen is released per minute, using an accurate stopwatch. I will keep the test tube, delivery tube and stopwatch the same throughout the experiment. And between each experiment I will refill the test tube with hydrogen peroxide so there is enough to last through the whole minute. And I will get the potato cylinders from around the same place in the same potato, because different places or different potatoes must have different enzyme concentrations. This will keep my results as accurate and reliable as possible. I will take each reading 3 times to make sure the results are reliable and consistent. ...read more.


I am going to use 20ml of hydrogen peroxide so there is enough to stay active all through the experiment, and so that there is enough to keep all the potato pieces submerged under the hydrogen peroxide. I have not controlled PH and temperature meaning I have not got a result as accurate as it could be. I have controlled the substrate mole amount because if I hadn't then the result I get might be because of the increased or decreased substrate molecule amount instead of the varying enzyme concentration. This is a plan of the table I will use to record my results. Risk assessment * Hydrogen peroxide is very corrosive, all spills on the skin need to be rinsed under cold water, and any spills on the bench need to be wiped up. * Goggles must be worn if you do not wear glasses. * If water is spilt on the floor it must be wiped up to save injuries. Table of results Procedure List of apparatus: * 3 Test tubes/boiling tubes, (one extra just encase needed) * Delivery tube (that fits tightly to the test tube/boiling tube) * Water bath * 300cm3 of 2mole Hydrogen peroxide * 90 1cm pieces of Potato cylinders * Knife * Slate to cut on * Ruler * 10cm3 Syringe * Stop clock Instructions Before ...read more.


Evaluating your evidence I think my results came out as expected but my doubling theory did not come out as expected it did not match the prediction, I think I carried out a fair test though because I used very accurate equipment. I did not get any anomalous results my results increased at a steady rate until a certain point the line is straight so I don't think any of my results were anomalous. I think my procedure was accurate but if I had a device for cutting the potato cylinders to exactly the same length then it would be even more accurate. I think my results are accurate. I used the most accurate clock and measuring cylinder I could find in the department to measure my results, but if I had looked outside of the school equipment I could have got more accurately measured test tubes, and stop clock. I can be sure that my results are reliable because I did all my experiments three times on each amount of potato enzyme. I think I do have enough evidence for my conclusion because I can conclude that my doubling theory did not work but that the more 1cm pieces of potato I added the more oxygen was released up to a certain concentration where it still increased but at a slower rate. Emma White 1 ...read more.

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