Lock and Key
Apparatus list:
Five test tubes Dimpled tile
Starch solution Matches
Amylase solution Pipettes (1/gp)
Stop watches Splints
250ml beaker H20 bath set at 37˚C
10ml measuring cylinder
Iodine solution
Thermometer
Method:
- Place 2cm³ starch in a test tube
Half fill beaker with water of your chosen temperature.
Place test tube in it.
Place thermometer in at the same time.
- Put three drops of amylase to the starch solution.
Start stop watch at the same time the first drop goes in.
- Take a drop of solution and test it with the iodine solution every minute for 10 minutes to indicate when the starch has gone.
- Repeat whole experiment again for the next temperatures.
The temperatures that I have chosen are 18˚C, 28˚C, 37˚C, 56˚C, 78˚C.
Fair test:
I made this a fair test by trying to get the most accurate reading on the thermometer of the temperatures I chose. You get this by looking at the thermometer directly and not at an angle. To make this more of a fair test you could make sure the iodine is clean and make sure when you add amylase to the starch solution you add only 3 drops. When you add iodine to the dimpled tray you have to make sure it is not filled to the top and is more even. My results I think are very accurate because I marked my results carefully and I looked at different peoples results to see if they had the ones that I had or if their results are close enough to mine.
Safety:
In the science lab we had to consider safety rules, they were things like don’t
Don’t run because someone could be carrying hot water and you could get scalded. Put your bags and coats under the table so no one trips over them and injure them self. Don’t squirt people with the pipettes because if it was iodine it would stain their clothes. Don’t mess around because you could break some of the schools science equipment.
Results and observations:
The results labelled 1and highlighted red in the Temperature ˚C column are my results and the results labelled 2 and highlighted blue are someone else’s results so I can see if mine are accurate enough.
✓ = Colour of Iodine is blue/black which means starch is still present in the solution.
✗ = Colour of Iodine is orange which means there is no starch left in the solution.
My observations for this experiment I did were that the enzyme amylase doesn’t work as well in temperatures that are above or below 37˚C. The reason why it works so well at 37˚C is because this is body temperature and it works at its best to digest starch.
Analysis/Conclusion:
My results tell me that the enzyme amylase works best at 37˚C which is its optimum temperature for it to digest starch. I know this because my scientific knowledge tells me that amylase digests insoluble starch molecules into smaller soluble molecules of sugar. They can speed up the rate of a reaction and can be used over and over again. Every enzyme has a specific job which they stick to and do not change so amylase always acts on starch. Amylase works best at temperatures which are from 35˚C - 40˚C but if the temperature goes above 45˚C the enzymes become denatured and cannot work anymore. The role of the temperature in this experiment is to at what ˚C an enzyme works best at. At different temperatures an enzyme will work differently and act at different speeds. In terms of the collision theory the lower the temperature the less collisions there will be so the enzymes won’t work as well as it could. At temperatures higher than 18˚C the enzymes will start to work more efficiently because the higher the temperature the more collisions there will be.
Evaluation:
The procedure I used for this experiment was putting the test tube in the water that’s at a certain temperature with starch and adding amylase to the starch. I think this is the best way to test at which temperature amylase works the best. The quality of the evidence that I got from the experiment I think is reliable and not irregular because I collected two results one of which is mine and the other is from someone else to make sure mine is close enough to the best result as possible. One anomaly in this experiment could be that the iodine in the bottle already contained a little starch which spoilt the experiment. The procedure I did I think is very suitable and it doesn’t have much defects but they can easily be corrected.
You can make sure that the experiment you do can come out with the best results by making sure you have clean iodine, you don’t mix up the pipettes, you put only three drops of amylase to the starch, and you start the stop watch/clock when the first drop goes in. You could choose more temperatures for the experiment so you will get more results and see what temperatures it works best at. To make sure the results are accurate you should do the experiment with the different temperatures more than once and then after you can compare it with other peoples to see if your results are correct.
The evidence I gathered I think is sufficient enough to support my conclusion because my scientific knowledge tells me lots of things about the enzyme amylase and the optimum temperature at which it works best at. To provide additional relevant information to make this experiments results more accurate you could research a scientist who has done this experiment before and see the results you got and compare it to their results or you could do further work which will make sure you come out with the best results as possible.
