In terms of health and safety, there will be Bunsen burners and hot water involved in this experiment, so I need to be aware of the risk of burning. I need to make sure I have a clear space which I can work in and work cautiously. Also I will be using a knife to cut up the beetroot, so must be aware and avoid cuts. I should be able to avoid cutting myself by, like above, having a clear area and handling the knife with caution. Like any other experiment, I will be wearing safety goggles, to ensure I have covered eyes.
Apparatus
Knife
Ruler
Sterile forceps
Beetroot slices
Thermometer
Colorimeter
Stopwatch
Pipette
Size 4 cork borter
Water baths set to 0, 10, and 20 up to 70◦C
250 ml beaker
8 boiling tubes
Method
- To ensure I have the same size beetroot slices, I will cut them using a ruler, and using a size 4 borter to make sure they are all 1cm long.
- Pour 5cm^3 of water into the boiling tubes
- Place the slices of beetroot into each of the boiling tubes
- Then place these boiling tubes into the water baths set at different temperatures. (0, 10, 20, 30, 40, 50, 60, 70◦C)
- Leave for an overall time of 30 minutes, using a stopwatch to measure the time spent. 30 minutes is enough for the temperature to fully boil and have a full affect on the membrane of the beetroot.
- After the 30 minutes, remove the boiling tubes and shake the test tubes to liquefy the pigment in the water
- Place them in the test tubes racks
- In order to document the change, one uses the pipette to measure 2cm^3 of the water and dye solution.
- Place each sample into the colorimeter and measure the absorbency of each beetroot as shown on the monitor on the colorimeter.
Below are the results I obtained from the experiment.
From this set of results, I manipulated them into a visual graph in order to see the results a lot more clearly.
0 10 20 30 40 50 60 70
By looking at my results, one can see that there is a steadily increasing rate of percentage absorbed correlating with the temperature increased. The amount absorbed was measured by the colorimeter, in which is a reliable measurement to base my recordings on. The reason this graph doesn’t proportionally increase is because there are two results at the beginning which are abnormally high if following the general pattern in which the other results correspond with. These first two results, I believe to be anomalies because they don’t keep up a correspondence with the line of best fit. These two recordings could be of result to errors that I made during the experiment. By excluding these two anomalies, I could say that there was a huge correlation between the raise in temperature and the membranes of the beetroot. This means that the overall temperature does have an effect on the structure of the membrane as there were clear changes in the structure of the membrane. My results show that the higher the temperature is, the more permeable the beetroot’s membrane becomes, as the more it absorbs.
There were some systematic errors that occurred while conducting my experiment. These included the fact that in order to make sure the beetroot cut outs were not to be affected by bacteria; I in fact had to cut them all out at the same time, which is hardly possible for one person to do. This could have overall affected the reliability of my results because the beetroot slices could have been affected from the beginning. Because of the amount of pieces I had to handle, there was a great chance that some were also in the water longer than others. This would have allowed some of the membranes to be more broken down because they spent a longer amount of time in the water. This could also be a reason as to why my first two set of results were considerably higher than the others. They could have spent longer time in the water, or could have also been affected by possibly bacteria beforehand. To avoid this next time, there should be more than one person working on the experiment in order to collect an accurate account of results.
There were also many random errors that may have occurred during the conduction of my experiment. Because the readings on the colorimeter were very reliable and accurate as it was a machine reading, I felt fully confident that these results were as accurate as they could be. The only other thing that I could have easily got wrong was when I was meant to shake the test tube gently. I had no general idea how much I was shaking each test tube to mix up the dye and pigment solution, and could have shaken one test tube more than the other, giving some of them an unfair reading on how much it had been absorbed. Furthermore, the colorimeter, although I’m very sure it was fine, could have not been functioning properly. Taking this into consideration, I could have repeated the experiment to obtain much more results.
Overall, I can conclude by saying that this experiment proved my prediction with the use of biological knowledge and reliable results. I can successfully conclude by saying that the change in temperature will change the overall structure in the beetroot membrane by making it more permeable the more the temperature increases.
