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

Why did the colour leak out of cooked beetroot?

Extracts from this document...


Aim: The objective of this investigation is to find out, "why does the colour leak out of the cooked beetroot?" and the aim of this is to investigate the effect of temperature on cell membrane. This experiment allows us to see the permeability of the membrane structure of beetroot. Beetroot contains red pigments called betalains, located within the cell vacuole. Normally, the pigment cannot pass through membranes but they leak out when the beetroot is boiled. And therefore by observing the beetroot under different temperature, I will be able to determine the effect of temperature on cell membranes. Hypothesis: As the temperature increases, so does the percentage absorbance of the beetroot pigments. Fair testing: Definition: 'Fairness' implies that the outcome of the activity truly depends on what is being investigated, and is not being distorted by other external factors. Therefore a fair test is one where all the variables are kept constant or the same, except the variable that is being investigated. A variable is anything that can change and which may influence the outcome of the investigation. List of variables: The different variables are: > The amount of distilled water > The temperature of the water > The length of the beetroot. - 1 cm in length Variables that needs to be controlled (independent variable) ...read more.


2 Place the slices in a beaker of distilled water. Leave overnight to wash away excess dye. 3 Next day, place eight labelled boiling tubes each containing 5 cm3 distilled water into water baths at 0 ?C, 10 ?C, 20 ?C, 30 ?C, 40 ?C, 50 ?C, 60 ?C and 70 ?C. Leave for 5 minutes until the water reaches the required temperature. Place one of the beetroot sections into each of the boiling tubes. Leave for 30 minutes in the water baths. 4 Remove beetroot sections; shake the water/solution to disperse the dye. 5 Switch on the colorimeter and set it to read % absorbance. 6 Set the filter dial to the blue/green filter. 7 Using a pipette accurately, measure 2 cm3 distilled water into a cuvette. Place the cuvette into the colorimeter, making sure that the light is shining through the smooth sides. 8 Adjust the colorimeter to read 0 absorbance for clear water. Do not alter the setting again during the experiment. 9 Place 2 cm3 of the dye solution into a colorimeter cuvette and take a reading for absorbency. Repeat the readings for all the temperatures. 10 Present your results in an appropriate way. Prediction: I predict that as we increase the temperature of the water solution more pigment will leak out. ...read more.


To control all this man made errors, the best way to obtain precise readings is by taking the reading from the calorimeter more than once after taking out the beetroot from the test tube. So basically, I repeated my experiment twice for accuracy and there were no anomalies. But still there are many things that could have affected my results and these are as follows: * The length of beetroot cut out - if a larger length was cut, more of the pigment would have been released increasing the percentage absorbance. * The temperature of the water was not constant as it wasn't left for the specified 30 minutes. To further improve my results or to have more confidence in my conclusion I could have done the following: 1. I could have taken measurements in shorter temperature intervals for example instead of measuring from 10?C, 20?C, 30?C ---- I could have used 0?C, 5?C, 10?C and so on... with an interval of 5?C. 2. I also could have done the same experiment perhaps with another plant to see if the relationship between the temperature and its effect on cell membranes are the same. 3. The experiment can be modified - using different apparatus such as a more accurate colorimeter, which measures light at narrow range of frequencies. ...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 Exchange, Transport & Reproduction 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 Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    Biology coursework planning - the effect of lead chloride on the growth of cress ...

    5 star(s)

    Repeat the above steps for the remaining concentrations of lead chloride. These can be found in the table on the next page. For volumes of 5ml and under, use the 5ml syringe, for volumes between 5ml and 10ml, use the 10ml syringe and for volumes above 10ml, use the 20ml syringe.

  2. Marked by a teacher

    An investigation on the effect of temperature on beetroot membrane structure.

    4 star(s)

    Centre of beetroot appears to contain more betalain than the external parts. Beetroot washed in distilled water 10 minutes By using a stopwatch This is to ensure all betalains from damaged cells is washed away. Wavelength of light in colorimeter 470 nm To select wavelength of light an optic filter

  1. Marked by a teacher

    Osmosis. Aim: To find the molarity of potato tubers cell sap. BIOLOGICAL ...

    4 star(s)

    Negative change was seen as well in the case of 0.75 molar, 0.50 molar and 0.25 molar glucose solutions. In case of 0.75 molar, it was -7.33%, for 0.50 molar, it was -4.00% and in case of 0.25 molar, it was -0.67%.

  2. Marked by a teacher

    The Effect Of Temperature On The Permeability Of The Cell Membrane

    3 star(s)

    This is used to measure the light absorbency through the solution containing the anthocyanin in the cuvette so that I can work out how much diffusion took place Why? This is a accurate way of measuring the amount of light absorbed * Measuring Scales- [This is a very accurate piece

  1. Marked by a teacher

    Effect of temperature on membranes

    3 star(s)

    and the help of carrier proteins to transport molecules across the membrane. Diffusion is the net movement of molecules from a region of higher concentration to a region of lower concentration down the concentration gradient until dynamic equilibrium is reached.

  2. Investigation on Osmosis using a potato.

    It may also be because the potato cylinder was taken from a part of a potato that had very little sucrose making it transport more water. But this again may not be entirely true. Graph to show results on third test This test is a lot easier to analyse then when on a table but rather on a graph.

  1. the role of the microbiology department

    By doing this, the same tool can be reused in different experiments without fear of cross-contamination.The loop is used to cultivate microbes in Agar jelly and to use the streak manouvre to transfer microbes. Incubator (microbiology) In microbiology, an incubator is a device for controlling the temperature, humidity, and other conditions in which a microbiological culture is being grown.

  2. Free essay

    Why does the colour leak out of a cooked beetroot?

    Diffusion is the movement of molecules or ions from an area of their high concentration to an area of their low concentration. Diffusion will continue until the substance is evenly spread throughout the whole volume. Small-uncharged particles diffuse across the cell membrane, passing between the lipid molecules as they move down the concentration gradient.

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