We are experimenting with the effects of temperature on the membrane, so we will place the samples of beetroot into a water baths of varying temperatures and measure the colour change in the water.
Aim:
Is to determine what effect an increase in the surrounding temperature around the beetroot's cell structure has on the plasma membrane.
Hypothesis:
An increase in temperature will damage and denature the plasma membrane causing the cytoplasm and other substances contained within the membrane to leak out.
Equipment and materials:
- Beetroot Plant Corers (various diameters)
- White tile
- Heatproof mat
- Bunsen burner
- Tripod
- Water Beaker
- Gauze Beaker
- Thermometer
- Colorimeter
- Distilled Water
- Test tube containing 20cm3 of distilled water
- Tongs
- Scalpel
- Stopwatch
- Paper towels
Method:
Before the experiment can start, the beetroot must first be prepared. To do this, we need the white tile and the corers. The same diameter corer must be used for all the pieces so to keep the surface area of each beetroot piece fairly similar. Collect a cylinder of beetroot, by pushing the corer into the beetroot and then remove it. The cylinder will remain inside the corer, so it must be pushed out with a corer of a smaller diameter. Once you have some uniform cylinders collected, they must then be cut into 5 pieces of equal lengths-3mm. Since the beetroot has been cut some of the cell membranes had been broken, which means some anthocyanin will leak out. This must be completely washed off to sustain the reliability of the results, doing so by drying the beetroot with paper towels. The water inside the water beaker is then to be heated to 85 Celsius using the Bunsen burner and tripod. Get another water beaker of a smaller size and place distilled 20cm3 of distilled water into it. Heat it to 20 degrees Celsius, remove the Bunsen burner from underneath the tripod place the 5 pieces of beetroot into the distilled water at the same time start the stopwatch. Keep the beetroot in the distilled water for 5 min. After 5 min, stir the solution 5 times to ix the solution to make the whole solution the same colour. Pore the coloured distilled water into a small cuboid container, which is able to fit into the colorimeter. Place this container into the colorimeter; place the lid on to prevent variables such as light affecting the result. Record the reading. This procedure is to be repeated again twice so you have 3 sets of data record for 20 degrees Celsius. Repeat the whole of the above, the only difference being the temperature. The other temperatures being used are 30, 40, 50, 60, 70, 80, and 90.
Results:
Conclusion:
After receiving my results I have come to the conclusion that my initial hypothesis was correct. This is due to the breakdown of lipids that make up the plasma membrane; holes appear within the membrane itself allowing the fluid to move freely. However anomaly results have occurred, I noticed that my hypothesis was only correct to a certain point. The results started to rise again after 70 degrees Celsius.
This is due to the temperature getting to high, the proteins within the cells begin to decompose blocking the holes, and this restricts the movement of the fluid. The anthocyanin is unable to escape the cell. Using the data I have found it can explain why cells cannot maintain life in extreme temperatures. Looking at the actually recorded data not the average result there were a few anomaly results including the first reading for 30 degrees Celsius. I predict that there may have been an error in the experimental stage as the result 22 was much lower than expected it was lower than any of the other results recorded up to 60 degrees Celsius. These results are not a good example for my hypothesis, there is no direct correlated pattern and many variables could have affected the results.
Evaluation:
The first problem encounted was the size of the beetroot pieces. The pieces could be the same in measurement but there mass could have been different and there surface areas differed to one another. This obviously affects the experiment and I should have weighed the beetroot pieces before the experimental stage. The other difficult variable to maintain was the temperature, when the Bunsen burner was removed from underneath the tripod. The recording of the reaction was 5 minutes. The temperature could fall dramatically in 5 minutes, which makes the results unreliable. Using distilled water, which is the clearest possible liquid was good. It meant that even the smallest variation in colour could be detected by the colorimeter. External variables were a problem, an example would be the wind coming through the window, it would blow heat to one direction disadvantaging other areas. If the experiment were to be repeated temperature stability would have to be resolved. A template for the beetroot could also be used.