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The effect of temperature on the break down of starch to maltose by amylase

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Introduction

Biology coursework by Nanjie Lu -The effect of temperature on the break down of starch to maltose by amylase Planning Aim I will be using many different temperatures to test the time for starch to be broken down into maltose by an enzyme. I will try to find out the shortest time it takes for the starch to be broken down, this will show what the enzyme's optimum temperature is. Factors that could affect my investigation There are many different factors for this experiment but I chose the temperature one to study. Other factors are pH (acid value), concentration, inhibitors are important too. Prediction *The best temperature for breaking down starch is between 60 and 70 degrees C. This is because this is the temperature at which the enzyme works most efficiently (Only 3 minutes). The information is from table 1. *At a temperature of 10 degrees C the enzyme did not catalyse the reaction, because when I makes test, the starch had not been broken down by enzyme. I think the starch molecules were not moving quickly enough. So they did not collide with the active site. When the temperature was 85 degrees C or higher the molecules did not work, because heat changes the shape of active site of an enzyme. ...read more.

Middle

6. When I see the colour has changed from black to orange then I am going to write down the time it takes. 7. I am going to measure the temperature at the end and stop the clock. I will repeat this method at different temperatures to find out the quickest time to complete this experiment. These will be 30?C, 40?C, 50?C, 60?C, 70?C, 80?C, 90?C and 100?C. I will make the amylase reach these temperatures by heating the water as show in the diagram. Iced water Temperature is 70 degrees water Temperature stat=1.0 degrees C Temperature end=0.0 degrees C Average=0.5 degrees C Temperature star=72.0 degrees C Temperature end=71.0 degrees C Average=71.5 degrees C Time (s) colour colour 30 black dark brown 60 black brown 90 black brown 120 black brown 150 black light brown 180 black light brown 210 black light brown 240 black light brown 270 black light brown 300 black light brown 330 black light brown 360 black light brown 390 black light brown 420 black light brown 450 black light brown 480 black light brown 510 black light brown 540 black light brown 570 black light brown 600 black light brown Accuracy * Record exact temperature in ?C at the start and end and find the average. ...read more.

Conclusion

Below 28?C the enzyme work so slowly it took more than 10 minutes (this result is from table one) to break down the starch. * Molecules move slowly into active sites. High temperatures * Above 95?C the enzyme did not break down starch. This is because the heat changes shape of active site. This is because the molecules are vibrating very quickly. The enzyme is denatured. Evaluation My procedure was successful because I found an accurate optimum temperature that was close to the preliminary optimum temperature. My evidence is reliable because the temperatures I plotted were the average of start temperature and end temperature. I have an odd result on table five graph and another odd result on the table three graph I am not sure why these results are wrong. To make the result more reliable I could use an electric heated water bath that would stay at the temperate I wanted exactly. Some of the temperatures that I plotted may not be very accurate because I use the average of start temperature and end temperature. I do not think my evidence supports a strong conclusion because the table three graph and table five-graph gave optimum temperatures that are 6 degrees C different. I could extend this enquiry by testing other enzymes and by testing for temperatures every 2 degrees C between 66 degrees C to 80 degrees C. 1 ...read more.

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