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

Beetroot practical

Extracts from this document...

Introduction

Why does the colour leak out of cooked beetroot? The aim of this experiment is to investigate the effect of temperature on membrane structure. I predict that as the temperature of the water in which the beetroot is placed increases, the amount of pigment leaked will increase. My prediction is based on the concept that cell membrane will breakdown as the temperature rises. Apparatus * Corer * White tile * A Beetroot * Automatic Water Bath * Segregated knife * A thermometer * Stopwatch Method: * First I took the white tile and the corer. Then collected a cylinder of beetroot by pushing the corer into the beetroot and withdrawing it. The cylinder remains inside the corer. * I collected 2 cylinders, and cut them into 8 pieces of 1 cm with a segregated knife. Because the beetroot has been cut some of the cell membranes had been broken, which means some pigments leaked out. ...read more.

Middle

Temperature % of absorbent 0 81% 10 110% 20 86% 30 103% 40 90% 50 15% 60 7% 70 8% (see graph next page) Analysis Through observation from the line graph that I have constructed it is quite certain that there is a similar pattern. There is a steady speed increase represented by a positive correlation. It shows that as the temperature increases the percentage of absorbance also increases. This means that more pigment diffused through the beetroot's cell membrane at higher temperatures. There is one exception, which is the beetroot that was situated within the cold water as this shows an absorbance of 0%. Evaluation There were a number of sources of error that may have affected the accuracy of my results. Firstly I had one stopwatch and timed all the water baths for fifteen minutes, so there was a slight delay however between the placing of the tubes in each water bath, as I had to walk to each water bath so it would have affected my reults slightly. ...read more.

Conclusion

It would also have been better to have had the time to repeat each temperature more times to make the results more reliable. Another limitation was cutting the beetroot into pieces. The pieces cut had roughly the same surface area to volume but not exactly the same volume. This would have had a slight effect on my results because the rate of diffusion of betalain particles across the plasma membrane is increased, as the surface area of the beetroot increases. So the slightly thinner and smaller pieces of beetroot I cut would have released more betalain from their vacuole. Conclusion I conclude that there are no apparent anomalies in my results and none of my sources are deem enough to make my results unreliable. However the sources of error and limitations in my results may have made my results slightly less accurate, but other students in my class found the same. ...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

Here's what a teacher thought of this essay


** This is a very limited piece of coursework that is lacking in a number of key areas that are needed to gain a good grade at A level.
To improve:
Research and Rationale.
There is no background theoretical material included in this report. Additional sources beyond readily available textbooks should be used to provide a context for the experiment and to assist in the planning. References should be included.
Planning. More thought needs to be focused on the key variables. Many of the important variables to be controlled are not described. The apparatus is listed but needs to be justified and full details included. The range of temperatures is identified but there is no indication as to why this particular range was chosen. No suggestions for repeating the collection of data are included. A pilot experiment would be helpful. There is no safety information included which is now a requirement for many examination boards.
Implementing. The data needs to be recorded in a suitably headed table and the precision of the data (only to one percentage absorbance unit) could be improved. Since only eight readings were recorded no data processing was appropriate and this would lose credit.
Analysing and Evaluating. No graph was included. The trends in the data need to be described correctly and the results should be explained using reference to basic biological knowledge. The limitations of the results should be discussed. The candidate needs to include suggestions for improving the reliability of the method.


Marked by teacher Stevie Fleming 26/07/2013

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

    The Effect of Ethanol Concentration on the Permeability of Beetroot Cell Membranes to Betalain

    3 star(s)

    The more transmition percentage, the less blue light is being absorbed and so the less betalain in the solution. Constant Variables There will be some variables which I must ensure remain the same for every part of the experiment as they will have an effect on the results; these are on the following pages.

  2. Marked by a teacher

    An investigation into the inhibiting effect of tomato juice on the germination of cress ...

    3 star(s)

    doing the experiment in a temperature-controlled room or doing all of the experiments at the same time. This is important because temperature affects the rate of enzyme activity and will affect the enzyme's controlling factors associated with germination. If the temperature is not kept constant anomalies will result.

  1. Permeability of Cell Membrane in Beetroot Cells

    A lab coat and goggles should be worn at all times. The beetroot's pigment is a crimson/mauve colour and stains deeply if it comes into contact with material; therefore the lab coat prevents the pigment from staining your clothes. The pigment that seeps out of the ruptured cells is called anthocyanin.

  2. To investigate one of the factors that affects the permeability of cell membranes.

    Evaluation: I generally obtained the results that I expected for my practical and therefore the procedure was generally suitable for the task which I used it for. I have drawn a line of best fit on my graph, which all my points are very near to, but as I said

  1. Core Practical Mint or Garlic Toothpaste? Testing anti-bacterial properties.

    Obviously using skin would render the results invalid, as it was not testing the hypothesis as the wrong thing was used. Also the skin is likely to be much weaker than the fibres. I think that next time I would cut the celery in half so that the inner fibres can be extracted more easily.

  2. Beetroot Core Practical (AS)

    Independent Variables My independent variable will be the temperature to see what effect this has on the membrane structure of beetroot causing it to release dye into the distilled water. I am going to be able to control this variable by using water baths set at certain temperatures and leaving

  1. Investigating the effect of temperature on the activity of free and immobilised enzymes.

    This is, however, only up to a certain point. Free enzymes The rate of reaction increases until 35�C, after which it starts to fall. There is still some glucose being produced after 45�C, but only very little. By 50�C the average reading is 0% and the enzymes have been completely denatured.

  2. TEMPERATURE ON BEETROOT PERMEABILITY

    When a protein is denatured, the secondary and tertiary structures are altered but the peptide bonds between the amino acids are left intact. Since the structure of the protein determines its function, the protein can no longer perform its function once it has been denatured.

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