• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Why does the colour leak out of a cooked beetroot?

Extracts from this document...


Why does the colour leak out of a cooked beetroot? Introduction I predict that as the temperature increases, more betalains pigments will leak out of the beetroot, causing the water to become darker. The rise in temperature will cause the membranes to become more permeable. Then as the temperature increases, the proteins in the membrane start to wobble. This then causes the hydrogen bonds holding their shape to break. This happens in channel protein and due to this the cell membrane structure cannot control what enters and leaves the membrane, causing the betalains to leak out. I predict that between 20�C and 60�C the proteins will start to denature at a faster rate. Planning The procedures used in the method, will generate appropriate measurements that I can test, because the measurements are very precise and accurate. The instructions are well explained and easy to follow ensuring that measurements and temperatures are also precise. The experiment is valid enough to repeat the experiment to ensure reliability. The thermometer is suitable because it will give accurate readings of temperature. The pipettes are also accurate because it will measure out exactly 2cm3 and 5cm3. ...read more.


The random errors may be reading the volumes, or not precisely measuring out the volumes. Carelessness, like not concentrating on times that is meant to use during the experiment (30 minutes). Or likewise, not taking care when measuring the temperature of substances, it could go over the temperature needed. The only alterations I would suggest would be to repeat the experiment 2 or 3 times to get an average. Risk Assessment * When cutting the beetroot into 1cm sections, take care when using the knife, these may be very sharp. * The temperature of the water will be very hot in some of the water baths; do not let it get on the skin, as this will scold the skin. Be careful not to bump into the water baths, this could spill the water, cause injury or cause people to slip and get injured. * When transferring the liquids from different boiling tube, use tongs or heatproof mats to prevent scolding of the hands. * Carelessness could cause the glass to break, causing an injury. * Ensure test tubes are kept in test tube racks, and keep all glass apparatus in the middle of the worktop. ...read more.


Anthocyanin is a family of pigments that give flowers, fruits and leaves of some plants their red or blue coloring. This has been ?shown by a steady increase in betalains which leaked out of plant cells, which was then measured by the colorimeter light absorbance, as the temperature increased. By analyzing the results, denaturing occurs between 400C - 500C. The breakdown of the lipids which make up the membrane which causes 'holes' to appear in the membrane, allows fluids to pass out freely, but ?when the temperatures begins to get higher, the proteins in the ?cells begin to break down as well which blocks some of the holes and ?therefore slowing down the release of anthocyanin. It is safe to say that the results have been repeated ?reliably however it still would have been beneficial to have repeated ?the experiment more times to make certain that the results were not ?gained through chance or by an external factor. Distilled water was used, which is the clearest possible liquid, meant that even the slightest deviation in colour ?could be detected by the colorimeter. Rianne Malcolm 12H ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Molecules & Cells essays

  1. Marked by a teacher

    Beetroot contains red pigments called betalains, located within the cell vacuole. Normally the pigments ...

    4 star(s)

    They Estimated that the membrane was so thick, with the introduction of the electron microscope, membranes could be clearly seen for the first time. Plasma membranes of both animal and plant cells showed a characteristic three-layered (trilarninar) appearance. As we apply heat on to the beetroot, this denatures the proteins

  2. Marked by a teacher

    An investigation to examine the effects of temperature on membrane stability in beetroot, by ...

    3 star(s)

    be assured that the diameter of the samples will always be the same if I use the same cork borer each time. However, with the cuboids, it is much harder to regiment the size and shape as it is almost all done by eye.

  1. Marked by a teacher

    Core practical(Why does the colour leak out of cooked beetroot?)

    3 star(s)

    . * Bunsen burner: care must be taken other wise it you may burn your hand. Result:- Temperature?C %Transmission 85 2 75 9 65 31 55 85 45 87 30 75 25 96 15 93 Conclusion:- My hypothesis was proven as the temperature increased the leakage of beetroot cell membrane started

  2. Why does the colour leak out of cooked beetroot?

    Other variables which I am aware of but do not need to be controlled in this particular experiment are: ?The pH level of the beetroot. If I needed to control the pH of the beetroot then I could do so by using a pH probe at various times throughout the experiment.


    So more or less damage may have occurred to the membranes of the beetroot, depending on how long each of us left our beetroot for in the water baths resulting in more or less pigment getting leaked. For 35�C, there is a low light transmission of 3% which doesn't fit with the other results because it's slightly lower.

  2. Why does the colour leak out of cooked beetroot?

    sizes Use the same cork borer and measure the 1cm pieces carefully A larger piece of beetroot will have a greater surface area for the dye to diffuse out of A larger piece would lose more dye so show a greater % absorbance Random, as all of the pieces will

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work