Why does the color leak out of cooked beetroot?

A-Level: Biology

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Because of their properties in a phospholipid bilayer, the hydrophilic heads are always on the outside of the membrane and the hydrophobic tails are always on the inside of the membrane. The other molecules which are indented into the phospholipids play vital roles, particulary Proteins. Proteins are made up of coiled and folded strings of amino acids which are very strong. However by adding too much heat to them it will cause them to loose their tertiary structure and start to unwind. Because one of the jobs of the proteins is involved in the transport of substances in and out of the cell the proteins will no longer able to carry out this job effectively. Thus more color will be lost.
Expected results- After finding out about the temperature and how this affects the rate of reaction the graph should to look as follows:

The amount of dye released will be directly proportional to the increase in temperature. This is because as the temperature is increased the energy of particles increases as they absorb more thermal energy and so move around faster and collide more often. This will result in the beetroot losing some of its colour. When the temperature is low the energy of the particles will be small and so it will not cause much of the dye to leak out. However increasing the temperature will cause the partially permeable membrane of the Beetroot to become damaged and so it will be less rigid. The higher the temperature of the water the higher the reading will be on the colorimeter as less light will pass through.


Method-
Apparatus & materials- The following will be needed in order to carry out the experiment
• Laboratory coat, disposable gloves and goggles to ensure safety. Goggles will ensure that nothing gets in to the eyes and that they are protected from the caffeine. Laboratory coat and gloves will make sure that clothing and the hands are protected.
• A size 4-cork borer will be needed to extract the beetroot pieces. Also a ruler and knife will be needed to ensure that all the beetroot pieces are cut to the same size. A white tile will be needed to cut the beetroot pieces on so that the workbench does not get stained. Tongs will also need to be when handling the beetroot pieces to make sure that they do not come in contact with skin and that they do not get damaged when handling them.
• 8 boiling tubes will be needed for the different temperatures. A tube rack will also be used to ensure that the tubes are ob a stable flat surface and that they are not constantly handled. The tubes will need to be numbered in order to avoid mix up.
• A measuring cylinder will need to be used to add the different amounts of water to each boiling tube. A 10ml measuring cylinder will be used as the small measurements will ensure that the amount will be more accurate. Distilled water will be used as normal tap water contains many impurities.
• To obtain the different water temperatures a Kettle will be used to warm the distilled water. Additional water will then be added to the boiling water to get the reacquired temperatures. A thermometer each for all the boiling tubes will be needed to read the temperature of the water, as all the temperatures will be different. Also the use of thermometers will ensure that the correct temperature is obtained.
• A stopclock will need to be used to make sure that at exactly 30 minutes a sample of the different waters is taken. A stopclock will be much more accurate to use than just timing from a watch or normal clock as it can be ensured that the clock is stopped at the right time. Also if it is stopped late the extra seconds or milli seconds can also be recorded.
• A Pipette will need to be used to transfer 2cm of the different dye in 8 different cuvettes. A pipette is much appropriate to use than a beaker or measuring cylinder as only small measurements are needed therefore the measurements will be more accurate and the results valid.
• The cuvettes will need to be placed in the colorimeter, which will read the colour absorbency for the different samples of water. This way it is much more accurate than just estimating the colour absorbency.
Hypothesis: As the temperature of the water baths around the beetroot is increased so will the rate of reaction causing more dye to be relased.
Method: Gather all the apparatus before the start of the experiment so that it does not affect the concentration and care taken during the experiment Make sure that all the apparatus is clean and that no substances are left behind in the apparatus which could affect the validity if the results. If a tuber is rinsed make sure that it is thoroughly dry before using it so that the volume of water is not un-equal. Place the tubes in a rack so that there is a stable surface to work on and than accidents are minimized. The tubes should be marked one-eight so that there is no mix up between the tubes.
Before the experiment is conducted the beetroot pieces will need to be prepared. Using a size 4 cork borer, a knife, ruler and white tile 8 identical pieces of beetroot which are 1cm in length will be cut. By using the same size cork borer and cutting all the pieces to the same length will ensure that the surface area of each beetroot is the same so that the measurements for the dependant variable are accurate and precise.
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