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An Experiment Into How Temperature Affects the Activity of a Enzyme - Catalase and Potatoes

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An experiment into how temperature affects the activity of a Enzyme Purpose: Explore how temperature affects the activity of a Enzyme (catalyse) Catalase - potatoes Background Information A catalyst is often present in reactions to induce or speed up something that would naturally occur. It lowers the activation energy of a reaction, resulting in more reactions quicker. Usually they speed up a reaction without loosing or actually taking part, their presence allows the reaction to occur faster (or slower depending on the enzyme.) Alcoholic fermentation and other important industrial processes depend on the action of enzymes that are produced by the yeasts and bacteria used in the production process. A number of enzymes are used for medical purposes. Some have been useful in treating areas of inflammation; trypsin is used in removing foreign matter and dead tissue from wounds and burns. The following are uses for catalysts that I have found Process Enzyme Involved Description Brewing Enzymes present in yeast A mixture of sugar solution and yeast will produce ethanol (100% alcohol) and carbon dioxide. This process is called fermentation and is the basis of the beer and wine making industries. Baking Enzymes present in yeast This also depends on the fermentation process. The carbon dioxide produced helps the bread dough ruse. The ethanol evaporates during the baking process. Washing using biological washing powders Proteases These enzymes break down proteins found in stains (e.g. blood, egg) on clothing. Making Cheese Lipases These enzymes speed up the ripening of cheese An enzyme is a biological catalyst found within cells, and catalyse is an enzyme. ...read more.


4 2 Too fast to measure 4 1 2.14 3 1 3.25 2 1 3.48 1 1 4.2 0.5 1 5.07 The experiment was started with 4ml of hydrogen peroxide and reacted it with 2g of liver. It proved to be much too fast so immediately it was apparent that the measurements needed to be lowered to decrease the reaction time. The reaction time needs to be lowered so I can read the measurements, and therefore get accurate results. For good results I would need the reaction rate at room temperature to be fairly slow as looking at my research the reaction time should decrease with a rise in temperature, with the fastest reaction time being around 37�c. After the first trail I changed the amounts of both liver and hydrogen peroxide to try and get a suitable time, however this proved difficult, as even with 0.5 ml of hydrogen peroxide the experiment only lasted 5 seconds. We have learnt from this experiment that reacting with liver is not sensible as we will not be able to get accurate results due to its incredibly fast reaction rate. I therefore suggest we use something that will react at a lesser speed than liver, potato. Potato contains the same enzyme as liver - catalyse, however it will not react as fast WHY? Fair Test It is essential to make sure that any experiment we do is fair and accurate and to make sure that this is the same, I shall be considering the following things during my experiment: * Temperature - I will monitor the temperature of the water bath with a thermometer and adjust it accordingly to get the most accurate temperature I can. ...read more.


The optimum temperature was around 40 ?C after this point the experiment began to take longer until at 60?C the enzyme no longer worked (effectively) at all. Conclusion As I have stated previously the enzyme worked better and better as the reaction was heated. This was due to the fact that the molecules were receiving more energy, and therefore the particles were moving faster, resulting in more (successful) collisions and therefore more reactions. However when the temperature increased too much the enzyme denatured and was no longer able to 'hold' the reactant. This meant that the enzyme was totally useless and had no effect on the reaction. The molecules were not colliding and reactions were unsuccessful. The activation energy of the experiment had been drastically increased and therefore the experiment was not working in the conditions. Evaluation The experiment had some unexpected results. I was expecting anything after 50?C to not react at all as the enzyme should have denatured, however in one of the three results the experiment got a reading. I think this was an error with the experiment. Aside from that the other results were as expected, and the experiment went well. Extension I think we could extend the experiment by reducing the increments of ?C that we went up in. This would give us a more accurate picture of the time the enzyme denatured. We could experiment with other concentrations and temperatures (into freezing.) We could use other enzymes, or compare them to some industrial catalysts. 1 Catalyst Experiment Page Steve Green ...read more.

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