How Temperature Affects the Ability of Amylase to Break Down Starch


Abstract

Several experiments were conducted in order to understand how easily the enzyme amylase can break down starch depending on temperature differences. Using beakers, test tubes, eye droppers, ice, water, iodine, starch, amylase, an electric hot plate, thermometers, and a test tube rack, a total of seven experiments were conducted. Based on the results, it was concluded that amylase tended to break down more starch in warmer conditions compared to cold  Also, it was noted that amylase could break down starch more if it had a longer time to break it down.


Introduction

Amylase is an enzyme used within human body that breaks down starch. It usually works in the normal body temperature which is 37 degrees Celsius. In this series of experiments, amylase was to break down starch in very extreme temperatures as well as in just slightly higher and lower differences of the normal body temperature. Time was also a variable in these experiments because depending on how much time it had to break down starch made a difference in how much starch the amylase could break down. Would more starch be broken down if the amylase was left in the starch for a longer time before the iodine was added? Did amylase work as well when it was introduced to extreme heat or extreme cold? The general hypothesis was that amylase would not like extreme temperature conditions and would not break down as much starch as it would in the normal body temperature.

Materials and Methods

Materials:
  1. 4 beakers
  2. 14 test tubes
  3. eye droppers
  4. ice
  5. water
  6. iodine
  7. starch
  8. amylase
  9. electric hot plate
  10. thermometers
  11. test tube rack
  12. stop watch
Methods:
The first experiment conducted was the hot experiment. To test how well amylase would break down starch in a very hot temperature, 100ml of water was put into a beaker with a Celsius thermometer and heated until boiling (100 degrees Celsius) using the electric hot plate set on high. When the water was boiling, two test tubes were placed into the hot beaker. One had 2ml of starch in it and the other (the control for all of these experiments) had 2ml of water in it. The test tubes were then allowed to heat in the water-filled beaker. Next, two drops of amylase were added to each of the test tubes. After waiting thirty seconds, the hot plate was turned off and the beaker with the test tubes in it was taken off the hot plate and 1ml of iodine was added to each test tube.
Next was the cold experiment. After filling a beaker with 100ml of water it was  cooled by adding ice until the water reached 0 degrees Celsius, the same procedures used for the hot experiment were taken. There were two test tubes of 2ml of starch and 2ml of water place in the cold beaker. Two drops of amylase were then added to each test tube and after thirty seconds had gone by, 1ml of iodine was added to each test tube.
After performing these experiments with very high and very low temperature conditions, it was time to test the amylase with starch at normal body temperature. One test tube contained 2ml of starch and another, 2ml of water. A thermometer was placed in each test tube. One person held the test tube containing water and the other held the one with starch. When the warmth of the hands had heated the water and starch up to 37 degrees Celsius, 2 drops of amylase was added to each test tube. After thirty seconds, 1ml of iodine was added to each test tube.
Next, experiments were conducted with just small variations of the normal body temperature to see if amylase would still break down starch if the temperature change less extreme. A beaker was filled with 100ml of water and heated using the hot plate until it was 45 degrees Celsius (8 degrees higher than normal body temperature). A test tube of 2ml of starch and a test tube of 2ml of water was then added to the warm water. Two drops of amylase were added to each test tube. After thirty seconds, 1ml of iodine was  added to each test tube. The same experiment was conducted again accept this expiriment  was 8 degrees cooler than normal body temperature (29 degrees Celsius). A beaker with 100ml of water was cooled to 29 degrees Celsius using small chips of ice to lower the temperature until it was correct. Amylase was added and then after 30 seconds 2ml of iodine was added.
Each of the experiments described above was repeated again accept the time variable was changed to 1 minute rather than 30 seconds.

Results
Prior Observations described bellow tell the appearance of the starch and water prior to adding 2ml of iodine to them.

Hot Experiment:
Prior Observations:
-water is clear in color
-starch is cloudy and translucent

Post Observations:
-water is orangish brown
-starch is dark reddish brown

Cold Experiment:
Prior Observatons:
-water is clear in color
-starch is cloudy and translucent

Post Observations:
-water is orangish brown
-starch is dark reddish brown

Body Temperature Experiment:
Prior Observations:
-water is clear in color
-starch is cloudy and translucent

Post Observations:
-water is light orange
-starch is light brown

8+ degrees body temperature experiment:
Prior Observations:
-water is clear in color
-starch is cloudy and translucent

Post Observations:
-water is light orange
-starch is light brown

8- degrees body temperature experiment:
Prior Observations:
-water is clear in color
-starch is cloudy and translucent

Post Observations:
-water is light orange
-starch is dark reddish brown

Hot Experiment (waiting 1 minute before adding iodine)
Prior Observations:
-water is clear in color
-starch is cloudy and translucent

Post Observations:
-water is light orange
-starch is very light brown

Cold Experiment (waiting 1 minute before adding iodine)
Prior Observations:
-water is clear in color
-starch is cloudy and translucent

Post Observations:
-water is light orange
-starch is dark reddish brown

Discussion/Conclusion

The results of this experiment reveal that amylase requires a specific temperature in order to function properly.  Temperature is an important factor in determining how an enzyme functions. When the temperature of an enzyme changes, so does the 3D structure of the enzyme. The 3D structure is crucial for the enzyme's ability to act as a catalyst. The shape of the enzyme makes the enzyme sensitive to what sub-straits it breaks and indicates where on the active site it will interact with the sub-straight. As the structure of the enzyme changes it becomes less efficient because the molecules that the enzyme normally targets (sub-straits) no longer fit into the active site and therefor the enzyme cannot interact with them as it would have normally.
The reason the experiments were repeated with 1 minute instead of 30 seconds is because each of the 30 second experiments tested positive for starch. From the 1 minute experiments we concluded that amylase works better at extreme hot temperatures rather than extreme cold temperatures and it works best around body temperature but the enzyme takes about 1 minute to break down all starch.
References

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