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How will whether the concentration of hydrogen peroxide when reacted with potato, determines the rate and volume of oxygen gas emitted?

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How will whether the concentration of hydrogen peroxide when reacted with potato, determines the rate and volume of oxygen gas emitted? Aim My task is to investigate whether the concentration of hydrogen peroxide when reacted with potato, determines the rate and volume of oxygen gas emitted. Background Knowledge Enzymes are complicated chemical substances found in all living things. They act as catalysts. A catalyst is a chemical substance, which speeds up a reaction but does not get used up during a reaction. Enzymes are made in cells and can be used up many times. Enzymes are specific, thus meaning that an enzyme, which acts on one substance, will not act on another one. Thus an enzyme, which breaks down proteins in to amino acids, will not break down starch into maltose. The shape of Enzyme A would determine which substance it would combine with, only a shape that exactly fits into enzyme A is adequate. Whereas it would not fit into enzyme B, therefore they are specific. Another reason is also a reaction occurs in stages: Starch > maltose (stage1) Maltose > glucose (stage 2) Each stage requires a different enzyme. The substance on which an enzyme reacts is called a substrate, which in our case is the hydrogen peroxide (H2O2). ...read more.


Remove bags from the area of experimentation. When using the scalpel, always take care, in cutting the chips. Always cut on a white tile, and hold them so that they will not move whilst cutting them. When using the cork borer, make sure your hand supporting the potato, is not in the way. Apparatus Stand, Boss, Clamp Test Tubes Scalpel White tile Stop Watch Delivery Tube Bung Measuring Cylinders Potato Hydrogen Peroxide Distilled Water Ruler (mm) Diagram Method 1. Set up experiment as in diagram 2. Place the potato on the white tile, and using a cork borer, extract 5 pieces of potato. 3. Place the 5 pieces of potato on the white tile, and measure their length. 4. Using a scalpel make each length 4cm. 5. Get 5 test tubes and label them 1-5, and using the table below, pour the correct amount of solution (using a measuring cylinder into them) regarding the test tube number. 6. Then start with test tube 1, and put a piece of potato in the test tube, start stopwatch, and replace the bung. After 30-second intervals, measure the volume of oxygen produced, by checking the amount of water in the measuring cylinder. 7. To test for oxygen, take a glowing splint and check if it relights when it meets oxygen from the measuring cylinder. ...read more.


Evaluation My graph and my results both agree with my prediction, however there are two anomalies, which show that my results and method were not accurate enough. But they both show that as concentration of hydrogen peroxide increases so does the rate of reaction. My prediction is correct. There may have been many experimental errors: Firstly, the length of all potatoes pieces may not have been accurate, due to the poor way in which I used the ruler, or the smaller less accurate scales. Another factor that could have affected the experiment is the time taken during replacing the bung, and the starting stopwatch. Also, the way in which the delivery t rube was held, made it bend and thus stop gas from To make the experiment a success, one could have used to people so that the process in replacing the cap is faster and thus less oxygen is loss. Another factor in which could have helped my experiment is the apparatus used, if a more accurate ruler, which measures in millimeters was used to give the length of potato. Also to improve my experiment, I would have taken more result, to improve the accuracy. To further my investigation, I would probably investigate the factors of surface area, and temperature. This would give me a wider perspective on enzymes and thus I could analyze it further. ...read more.

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