Enzyme (Lipase) - Fat particle -
The diagram above shows the likelihood of the enzymes bumping into a fat particle.
I first thought that the lower the concentration the faster the reaction would happen. I thought this because the less fat particles there are, the less work the enzymes have to do. However, this is not the case because the more fat particles there are, the more chance there is of an enzyme bumping into it.
Plan
Input Variable
My input variable is the Sodium Carbonate Solution (the buffet), the phenolphthalein, the lipase. These are all the things that I will not be changing the amount of in this experiment.
Output Variable
My output variable is the concentration of the substrate. The concentration will change with every test, because I add different amounts of milk and water to weaken the concentration
Step By Step Plan
- Have two test tubes.
- Add 5 ml of the substrate (milk) to each test tube.
- Add 5 ml of Sodium Carbonate Solution (buffer) to each test tube.
- Add 5 drop of phenolphthalein to each test tube. This should make the solution turn pink.
- Add 1 ml Lipase (enzyme) to each test tube.
- Start stopwatch immediately after adding the enzyme Lipase.
- Stir both mixtures with a stirring rod equally, until the solution has turned back to its original colour.
- As soon as the colour of the mixture has changed, stop the stopwatches and record the time it took.
- Repeat the test but this time diluting the substrate, follow the table below.
How will you make it A Fair Test?
I will try to make this experiment as fair as possible by keeping everything the same apart from the amount of milk and water I add as the substrate. Some examples of what I will keep the same are: the same source of water, the same equipment used, the same quantities of the different solutions. I will do each test twice to get a more accurate reading. Using a stopwatch for each test will make the timing of the test more accurate. The syringes that will be provided for us in this experiment will enable us to accurately measure our solutions.
Apparatus Used for Each Test Done
Pipette
Stirring Rod
Test Tube syringe
10 ml
Lipase
3 ml
Phenolphthalein Milk 2 ml 5 ml
Water Sodium Carbonate Solution
The amounts of different substances
Depends on what test you are doing
(Look at table above).
Results
What I Found And Why?
The solution that had the most amounts of fat particles in it, was the solution that reacted the quickest. This is because the more fat particles in the solution, the more chance there is of an enzyme bumping into it. The last set of results took the longest, as expected, but I think it took a bit too long it is almost double the amount of time it took to do the previous test. This could have been a mishap dew to the fact that there were many areas on which this experiment was an unfair test.
My Graph
On my graph the results go up the graph fairly equally apart from the last set of results. These sets of results seem to be unusually high. My graph has a positive correlation. This means the weaker the solution the longer it takes the enzyme to react with the fat particles.
Was My Prediction Correct?
Yes, my prediction was correct. This is because I gave scientific evidence for my explanations, I backed up my theories, and I gave examples of what I thought, which also helped explain my point.
Was It A Fair Test?
No, this experiment was not a fair test. This is because of several reasons. The force and speed I used to stir the solutions would have been different for every test. I used tap water for my experiment, which could have intervened with the experiment because tap water has chemicals in, which would lead to inaccurate results. As soon as you add lipase to the solution, the chemical reaction immediately takes place. When timing the experiment, starting the stopwatch as soon as the enzyme enters the solution is crucial. Therefore, we could have started the time too soon or too early, making the results unfair. It is also hard to tell when the solution has gone back to its original colour, so that is a reason why we did each experiment twice so we could get an average.
Was the your method of carrying out the experiment done well? Where there any Problems?
I think our method of carrying out the experiment was done well, because there were hardly any problems. Our only problem with carrying out the experiment was our own clumsiness. When stirring the solutions, I accidentally made a hole in the bottom of the one of the test tube, we had too stop the experiment and repeat this test, and this was our only problem, which was a minor set back.
How Could You Improve the Experiment
I could have improved the experiment by using distilled water instead of tap water. Distilled water is pure water, so there are no chemicals in it so there would be no chemicals interfering with the results. Having a certain amount of time I stir the solution with every experiment would make it just that much fairer, but it would still be unfair because I can not measure the speed I stir the solutions. In addition, I could have repeated the test more times to get results that are more accurate.
Ideas for Further Experiments
- Could test different enzymes with different substrates.
- Do not dilute the substrate and change the temperature.
- Change the amount of enzyme added.
- Do not dilute the substrate and change the pH of the solution.