Temperature Of The Starch And Amylase example essay topic

Aim The aim of my experiment is to investigate the effect of temperature on breaking down starch due to amylase. Background Info Amylase is an enzyme. It is found in the human body, in the pancreas and the small intestine. Amylase breaks down starch into maltose and other simple sugars.

This takes place in the salivary glands and starts the process of digestion and also occurs in the small intestine. Enzymes are: very potent biological catalysts, proteins, made by living cells, sensitive to changes in ph and temperature. They control metabolism. Effect of ph on enzymes: o Enzyme activity is greatest at the optimum ph for that particular enzyme. o Strong acid / alkali denatures (destroys) most enzymes Effect of temperature on enzymes: o Activity of most enzymes increases with temperature, reaching an optimum then decreasing. o Extreme heat denatures most enzymes. Effect of concentration on enzymes: o If the concentration of a reagent is increased then the rate of reaction will increase.

This is explained by the collision theory. In order to react chemicals must collide or hit each other. The more particles there are the more chance of collision. These collisions must occur with a minimum energy, the activation energy for the reaction.

Increasing the temperature helps the particles achieve this energy. Prediction I predict that at: 0 oc - the reaction will take a very long time or may not happen at all because enzymes are dormant at this temperature. 21 oc - the reaction will take quite a long time. 37 o - the reaction will be quite fast. I think this because at this temperature the atoms become highly charged and collide with more atoms causing reactions. This will be the fastest because it is the optimum temperature for amylase 65 o - the reaction will be quite slow as the enzyme is past its optimum conditions.

100 oc - the reaction will not happen as the enzyme has been denatured. Key Factors The key factors that will affect the amylase are: o The ph o The temperature o The concentration of starch o How long the starch and amylase are left in the water bath o The concentration of iodine o The concentration of amylase In my experiment I am only varying the temperature of the starch and amylase to see under which temperature the reaction works best. I will keep these things the same: the ph, the concentration of starch, the concentration of amylase, the concentration of iodine, how long we leave the starch and amylase in the water bath. If I don't control these key factors they could affect the experiment as well as the temperature and I would not be able to determine which caused the reaction so it would not be a fair test.

Method 1. Using a syringe, put 1 cm^3 of the starch suspension into 5 different test tubes and then into 5 water baths at different temperatures 2. Using a different syringe put 4 cm^3 of amylase solution into 5 more test tubes. Place these into the 5 water baths. 3. Start the stop clock and time 5 minutes.

Whilst the test tubes are getting to the required temperature use a pipette to add a drop of iodine to each well on the spotting tile. Wash out the pipette afterwards. 4. After 5 minutes, pour the amylase into the starch suspension in each water bath. 5. Take one drop from a tube with starch and one drop from a tube with amylase and add them to a well on the spotting tile.

A blue-black colour shows starch is present. A brown colour shows that there is no starch present. Wash out the pipette before taking each drop. Test all 5 test tubes in this way. 6. Repeat step 5 every 2 minutes until there is no colour change (a brown colour).

The temperatures I will be putting the starch and amylase in are: 100 oc, 65 oc, 37 oc, 21 oc and 0 oc. I will repeat the experiment at these temperatures 3 times each. Equipment Iodine 1 beaker of water Starch 2 syringes 1 spotting tile 1 stop clock Amylase 1 test tube rack A pen 30 test tubes Labels Thermometer 1 pipette Safety My experiment is not very dangerous but there are a few safety points. o Wear goggles - some of the solutions are harmful if they come in contact with your eyes / skin. o Wear a lab coat - some of the solutions will stain clothing. o Careful when boiling water - could cause a major burn if spilled on skin / eyes. How will you record results?

Every 2 minutes I will test my experiment until the solutions have stopped reacting. I will do this for all five different temperatures. I will repeat the experiment 3 times. This is a rough draft of what my result table will look like. Time taken for starch to disappear (minutes) Temperature (oc) 1st Time taken 2nd Time taken 3rd Time taken Average Time Analysis This is the results table for my experiment.

Time taken for starch to disappear (minutes) Temperature (oc) 1st Time taken 2nd Time taken 3rd Time taken Average Time 0 18 18 20 18.66 21 6 6 8 6.66 37 4 4 4 4 65 6 8 8 7.33 100 - - - - I chose to use the 0 oc and 100 oc because I wanted to see what happened at extremely low and high temperatures. I chose 37 oc because through research I found out that this was the optimum temperature for amylase. I used 65 oc and 21 oc because they are either side of the optimum temperature and would provide a good range to analyse and draw conclusions from. At 0 oc the reaction was very slow which coincides with my prediction.

This is because at this temperature the enzyme is lying dormant. At 21 oc the reaction was quite fast, this is because the atoms have some energy from the temperature and are colliding. At 37 oc the reaction was the fastest of all the temperatures as I predicted. This is because the atoms have the most energy at this temperature and are colliding more than at other temperatures. At 65 oc the reaction was just slower than at 21 oc. This is because some of the atoms are denaturing due to the high temperature and some are still colliding causing reactions.

At 21 oc the reactions were faster because it is closer to the optimum temperature for amylase. At 100 oc the reaction did not occur because the enzyme had denatured due to the extremely high temperatures. I stopped the experiment at 20 minutes as nothing had happened. This is what I thought would happen.

I have calculated the averages for the temperatures and they confirm these findings. My graph shows temperature measured in degrees centigrade plotted against the time taken for the starch to disappear. The graph shows negative correlation from 0 oc to 37 oc meaning that as the temperature increases as the time decreases, however from 37 oc to 100 oc there is positive correlation. This means as the temperature increases so does the time taken. Therefore the graph is a smooth curve. The lowest point on the graph is 37 oc as it is the optimum temperature and reacts the fastest.

The highest point on the graph is 100 oc, this is because the rate of the reaction cannot be measured as the experiment did not finish because the enzyme became denatured. Evaluation In my experiment the results were as I predicted from my research and background information. This is why I think my results are reliable. Also I found no anomalous results in my experiment. If I were to do this experiment again I would take more time and only test one temperature at a time to ensure the readings were completely accurate. Further work that could be done in relation to this would be to test the affect that changing the: ph, the concentration of starch and the concentration of amylase would have on breaking down starch due to amylase..