Biology Internal Assessment: Beetroot Juice

2123 Words May 13th, 2013 9 Pages
Biology Internal Assessment: Beetroot Juice

Hypothesis: As the temperature of the beetroot increases, the percentage of blue light shone through the mixture will be lower because more red pigments will pass through the membrane

Raw Data for experiment:
Quantitative Data- Since this experiment is done in a large group, I did the experiment with a temperature of 40 ˚C. | | Percentage of light that passes through the mixture (%) | Groups | Temperature (C°) ±0.5 | Reading 1 | Reading 2 | Reading 3 | Reading 4 | Reading 5 | A | 8.0 | 90.6 | 97.7 | 92.6 | 95.0 | 90.5 | B | 30.0 | 96.0 | 100.0 | 97.9 | 100.0 | 97.9 | C | 40.0 | 50.6 | 66.5 | 51.2 | 80.0 | 75.6 | D | 55.0 | 8.2 | 19.5 | 16.1 | 17.9 | 18.1 | E | 70.0 | 3.4 |
…show more content…
But after we increased the temperature from 8˚C to 35˚C, some bonds will break and the large molecules will split into smaller molecules, which means that the smaller molecules can diffuse through the membrane of the beetroot because it is just small enough to fit in between the lipid layers of the membrane. Therefore, as more betalain diffuses out of the membrane into the water, the red pigments will turn the water red according to the amount of pigments that passes through the membrane. The red pigments will also diffuse through the membrane because the water has higher water potential than the beetroot piece. As the temperature is higher, more bonds will break and more betalain will diffuse out of the membrane, causing a darker colour. Which is why as the temperature is low, it will have an almost see through mixture because the bonds have not brake which means it is not able to diffuse through the membrane of the beetroot.
A further investigation could be carried out to prove this point by using another plant with pigments like the skin of a mangosteen, which contains purple pigments called anthocyanin. (This will only work if the properties of the plant is similar to the properties of a beetroot, for example, Dry and

More about Biology Internal Assessment: Beetroot Juice

Open Document