Enzymes are found in the body and are used for the digestion of different food molecules. Amylase breaks down Starch to glucose while other enzymes break down other food molecules. Aim I am experimenting to investigate the effect of temperature on the rate of reaction for the enzyme amylase. Background Knowledge Some enzymes function best at 37oC, which is body temperature. This is a proven theory for the enzyme amylase. If the temperature is above or below 37oC these enzymes function slower, and therefore take more time to break down these food molecules.
However, at very high temperatures enzymes change shape and no longer carry out their function, they are said to be denatured. This is why I am testing to see how temperature affects the rate of reaction in detail. Amylase is also known as carbohydrase as used in the diagram below. (Diagram from http://www. gcsescience. com) Variables Amount of Glucose Present. This is the dependent variable of my experiment I will test this using iodine to display if there is glucose present. I will test this after the amylase has had enough time to break down the starch.
If the iodine should change black in the final solution, it means no reaction has taken place, but should it turn orange, a reaction has taken place. Temperature This is my independent variable. I will change this to investigate the effect it has on the rate of reaction of the enzyme amylase. This will be measured by a thermometer that can give me the most precise measurements possible. Test Tube This is a controlled variable in my experiment. I will use the same test tube for each stage in the experiment so that the test tubes I use will all have the same thickness and height.
Time Left To React This is a controlled variable in my experiment. The time before I test for glucose will remain the same in all my experiments all the way through. I will use a stop watch to measure this. Surrounding Temperature This is a controlled variable in my experiment. The room temperature will stay the same as I perform my experiment. Since enzymes are sensitive to change in the temperature. I will use a thermometer to measure the room temperature. Volume of Chemicals. This is a controlled variable in my experiment. Both the starch and amylase volumes will remain the same.
To ensure each time that the amylase is breaking down the same amount of starch as in the other tests. Concentration of Chemicals. This is a controlled variable in my test, to ensure that the starch is coming from the same solution and therefore the concentration is the same. Prediction This diagram is very simple (diagram from www. gcsescience. com but it shows that an enzyme is most active around 40i?? C and the activity decreases when it is both hotter and colder than 40i?? C. I came to this theory from my background knowledge I know that Amylase functions best at 37oC, which is body temperature.
If the temperature is above or below 37oC these enzymes function slower, and therefore take more time to break down these food molecules. I believe that this theory will be proven in my experiment. I believe as the temperature is increased the rate of reaction will slowly but noticeably get quicker, however once a certain temperature is reached. This certain temperature I believe is body temperature of 37 i?? C. Once the temperature is past this, I predict that the rate of reaction will dramatically drop.
I predict this because in other chemical reactions when the temperature increases the reaction happens faster since at higher temperatures the molecules in chemicals move around faster thus making them react I believe this to be different for the enzyme amylase since at higher temperatures or near to 60i?? C the enzyme is completely denatured and ceases to work. Method The solutions of starch and amylase are ready made up for easy access. The amylase is carefully poured slowly into a plastic graded test. The level is then checked by placing the graded tube on a flat surface and reading the level at eye level.
The starch is then measured in the same way in a different graded test tube. The temperature of the amylase is raised or lowered to the temperature needed using the smallest thermometer with the most precise measurements. Then the two substances are poured into one test tube and shaken 3 times. Then a pipette is used to extract 3 drops. The 3 drops are then placed into a Spot tile that already has 3 drops of Iodine placed in each tile the solution of starch and amylase is then dropped every 20secs or as closest to 20secs as possible.
If the iodine should change black in the final solution, it means no reaction has taken place, but should it turn orange, a reaction has taken place. The results are then recorded in the table and the same steps are repeated, however to change the temperature of the amylase for the experiment, the test tube will be heated until desired temperature is reached. For the best results my experiment will be repeated 3 times to ensure that I get the most accrete results possible. Equipment List Kettle, Water, Starch, Amylase, Iodine, 2 Large Beakers, 2 Test Tubes, Thermometer, Spot tile, Pipette, Test Tube Rack, Stop Watch and a graded test tube.