The ways in which I intend to deal with this-
- Calculate by how much the points on the graph are out by and label this onto the graph.
- Be thorough when checking measurements being placed into test tube.
- Keep a stopwatch in my possession at all times so as I can be sure as to the correct timing in which the solution(s) are left to filter, or left within the heat environment.
Such things as these are important because, it would be more in the interest of science to keep the results fair and constant. There would be no point in conducting the investigation unless I could ensure that I was performing a fair test, as the results would be incorrect and insufficient.
The evidence I plan to obtain is that heat does affect the clotting of milk and I will need a wide range of data collected from different heat environments to help prove this theory, as only a few temperatures would not be enough to secure foundations for my findings.
Ways of collecting fair data-
I intend on collecting fair data and one way in which I can accomplish this goal is that for every temperature I test, I will create three solutions and take data from all three then use that data to work out an average reading. Once I have my average reading I can then place it on the graph, this also helps me to keep the test fair throughout.
Preliminary work-
For my preliminary work I used the above method but since have made some changes, as my preliminary work enabled me to find any problems that lied in amongst the method. The only problem as such, that I found was the fact of the amount of rennin I originally set out to use. I found out from this that half the amount I was using was just as good for the experiment as the full amount first listed in my method.
In early stages of the preliminary work, my solution was not strong enough and there was hardly any clotting at certain temperatures. Another problem I encountered was when the solution was too strong, and the curds and whey could not be separated and this was preventing the whey from eventually being filtered through. Doing this work helped me to ensure that my method was a good way to conduct the experiment and, to help me get the right concentration of solution.
As another part of the preliminary work, I tested to see whether or not just heat alone would affect milk, which it did not. I did this by: placing milk in a test tube and heating above a Bunsen burner for a set time of ten minutes then tested it to see if it had clotted. This method proved that heat alone does not clot milk.
Other preliminary investigations included such things as, testing to see if rennin alone clotted milk, which it never. This test was done by, placing rennin inside 5 separate test tubes and adding milk to each. Every test tube was left for 10 minutes then checked to see if the milk had clotted, which it had not.
One other test was for seeing if acid would clot the milk alone. I accomplished this in the same way that I performed the rennin test. I placed measurements of acid in 5 separate test tubes, added milk and left for 10 minutes. After the time was up, I checked to see if the milk had clotted, and it had not.
Other acid preliminary tests were set up to see how much acid was needed to clot the milk, so as not to have to waste too much. Another problem with if too much acid was used was that, the milk clotted too much, and if not enough was used, then the milk would barely clot.
Prediction-
I predict that from this experiment I will find I am correct in assuming that heat does in fact, affect how much milk is clotted in a given time, but only after reaching the optimal temperature as this denatures the enzyme known as Rennin stopping it from clotting the milk. My reasoning for believing this is that over a certain temperature an enzyme such as Rennin would clearly denature and be unable to perform its task as normal.
Another reason for me believing this is that in an acidic environment the rennin would be able to perform it’s job better as the Hydrochloric acid is simulating the acid found in the digestive system of the human body [located in the stomach] which means that the rennin should be able to perform it’s job almost as well if not just as well as if it was inside the stomach.
Yet with no acid at all, the rennin would almost certainly be unable to perform as well as it would when working with the acid because it would not be like it’s own natural environment for performing the task.
Observation
Detailed Method-
- Measure out Hydrochloric acid and Rennin ready for use in solution to be placed into a test tube. Of which will contain 0.3ml of Hydrochloric acid and 0.5ml of Rennin after discovering it is just as effective as 1ml.
- After leaving in a beaker of water at a constant given temperature for a time of 3 minutes add 10ml of milk to solution in test tube.
- Leave the new solution of milk, rennin and acid in the given heat environment for the set time of no more or less than 10 minutes.
- Remove solution from the heat environment after the set 10 minutes has passed and place the contents of the test tube into a funnel of filter paper and leave to drain into a measuring cylinder for set time of 5 minutes.
- Take note and measure how much of the solution has filtered through into the measuring cylinder from the filter paper contained in the funnel.
- Repeat three times for each solution at heat variable.
- Take note of an average figure worked out from the 3 solutions at each heat variable and produce an easy explained graph to show my results and findings.
After these results I then decided to go into more detail with my findings and did extra Solution samples. For these I am using a separate table but all results will be filled in onto the same graph(s).
Analysing and Considering Evidence
From my evidence I have found that heat does in fact affect the amount of clotting in milk performed by rennin as my graph shows this. It starts of in an upward diagonal motion then after reaching a certain temperature it bows round and becomes a curve. This shows that after an amount of temperatures the rennin becomes denatured and can no longer perform as well as in its peak.
A line graph, which I have produced, as well as a bar graph, which does not show the results and evidence, as well as the line graph could best show the pattern in my evidence.
The pattern or trend in my evidence is that the efficiency of the rennin continues to grow as the temperature is increased until it reaches a peak position whereby after that heating the rennin causes it to perform its task to a less efficient capacity. Evidence of this trend or pattern in shown in the bow shaped line graph in which I have created from my string of results.
A line of best fit is not appropriate to this analysis as the graph clearly shows a bow rather than a straight-line format of a conventional line graph.
Conclusion from Evidence:
After looking at my own evidence taken down in this investigation I myself conclude that heat does affect the performance of rennin to a certain degree as after reaching it’s peak the rennin has become denatured and can no longer properly perform the task of clotting the milk and creating curds and whey from the filtrated milk after the experiment.
My scientific reasoning for this is that enzymes have to be within a constant temperature range and cannot perform their job outside of that range as they become denatured. It is the same with the enzymes found in your body such as protease, lipase and carbohydrase, if these enzymes are allowed to denature they can no longer perform their task and are rendered useless making it harder for the human body to digest food until more enzymes can be produced.
My results have coincided with my prediction and have proven that heat is a factor when rennin is performing the clotting of milk. This was proved as after a temperature of 40-50, the clotting had peaked and the amount of filtrate begun to reduce. Although this was proven there are still some errors with my results that may appear to be inconclusive but could well be out of line due to slight human error, which was also predicted in my prediction where I tried to think of ways, in which I could help myself to avoid such trouble. Obviously this could not be fully avoided and as a result I do have a slight kink in my results.
Evaluation
I myself believe that the task in hand worked well as my prediction was proved to be correct and my results showed this in a good manor up to the point of human error which could unfortunately not be avoided however it did not play a major part in my investigation therefore can be struck from the record and placed as a good investigation.
The evidence that I found was accurate but I could have improved it by going even further into depth with the detail in which temperatures I used and maybe even do a scale of 5ml rather than the 10ml scale. If needed the scale could be improved to the point of a 2ml scaled investigation as although this would take much longer to perform and assess it would be the most fair and show the best results. My graph on the other hand does show that the evidence was fair and almost 100% accurate throughout the investigation.
There were some anomalies that I have put down to a simple human error, as there is no evidence to suggest otherwise. Theses anomalies can be found in the scale of 50-60, 60-70 & 70-80 as these results seem to show a sudden drop.
Personally I believe that my method was good and correct for this procedure but could still be altered further still to get even better results. My reasoning for choosing to say that my method was correct is that after my preliminary work I changed my method to a more suited one and stuck with it throughout the investigation which was a success so I concur that my method was reliable in this instance.
I believe that I have enough evidence to draw a fair conclusion as all my results and graphs show that throughout the investigation my prediction remained true and consistent which was that the heat would indeed affect the rennin in performing it’s task of clotting the milk and creating curds and whey.
The ways in which I could improve my method are simple yet effective, for instance I could change these factors:
- Leaving the solution for longer periods at each stage for performing its task(s) so as to get the best possible results.
- Keeping a closer eye on how much of each ingredient is added to the solution and having more than one beaker at a time so as to be able to help keep the temperature constant.
Those would be the only factors that I would personally change in order to get the most fair, accurate and true results from my investigation.
