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

Effect of temperature on membrane permeability

Extracts from this document...

Introduction

Effect of temperature on membrane permeability Aim This investigation aims to determine what effect an increase in the surrounding temperature has on the plasma membrane of a typical plant cell structure. Hypothesis An increase in temperature will damage and denature the plasma membrane, which would cause the substances contained within the cytoplasm to leak out of the membrane. The investigation carried out was to see the "effect of temperature on membrane permeability". Different temperatures were used, ranging from room temperature to 87°C. Three test tubes were used to give a range of results. They were placed in a colorimeter, from which a percentage was recorded showing how much light had passed through. Figure 1 shows the results obtained from the investigation. A mean has also been calculated and included in the results. Temperature (°C) Test tube 1 (%) Test tube 2 (%) Test tube 3 (%) Mean (%) 23 98 96 96 96.67 45 95 93 91 93.00 53 74 73 73 73.33 65 54 45 34 44.33 87 1 1 1 1 Figure 1: A table showing the results obtained. From the above results it can be seen that as the temperature increases, the permeability of beetroot membrane increases. This shows that the plasma membrane must be denatured. ...read more.

Middle

The permeability of the beetroot membrane does depend on the temperature that it is placed in. Choosing a random temperature shows that the higher the temperature the more permeable the membrane, thus the more dye bleeds out of the membrane. The following will now outline an explanation of the above theory by referring to the cell membrane structure, diagrams and references will be used from the books listed on the cover of the coursework page. After collecting and correlating the results, I have come to the conclusion that the experimental hypothesis is correct, in that an increase in temperature will damage and denature the plasma membrane and cause the cytoplasm and other substances contained within the membrane to leak out. This has been shown by the steady increase in anthocyanin leaked out of plant cells as the temperature increases. A description of the plant cell's membrane structure will be given to show how temperature affects its structure. Figure 5 is a diagram of a typical cell membrane. Figure 5: A diagram showing the plasma membrane of a cell. The cell membrane (or plasma membrane) surrounds all living cells. It controls how substances can move in and out of the cell and is also responsible for many other properties of the cell. ...read more.

Conclusion

From 23°C to 45°C, the light % transmission does not decrease rapidly; the figures do not differ greatly. This could be due to the number of proteins being less denatured in 45°C as I would expect it to be, as this temperature would be considered above the optimum temperature that the plant cell could survive within. The betacyanin pigment of beet roots is normally sequestered in the vacuole and, by means of the properties of the tonoplast and cell membrane, does not leak into the cytosol or the extra-cellular sap of the beet root. Of course if the beet root is cut, cells are sliced open and the pigment spills out, but if the membrane is altered (phospholipid bilayer + proteins) more subtly leakage (diffusion) of betacyanin is induced. Although, the results help explain the hypothesis they may not be entirely reliable. Three readings were taken to increase accuracy; however this does not mean that the three results were accurate. Limitations in the apparatus could have encouraged this to occur, for example the standard deviation calculation for 65 C shows that the results are not reliable. There is also an anomalous result for 45 C. This is circled on the graph. The reason for the anomalous result could be due to a number of factors which will be discussed further in the evaluation. Manpreet Virdee Page 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our University Degree Cell Biology 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 University Degree Cell Biology essays

  1. The purpose of this investigation is to discover whether different respiratory substrates will affect ...

    There are two types of proteins that are used for facilitated diffusion. Channel Proteins form a water saturated channel in the membrane. This allows polar substances (usually ions) to diffuse across membranes. Carrier Proteins have a binding site for a specific solute and constantly flip between two states so that

  2. Immunology Practical: Enzyme Linked Immunosorbent Assay (ELISA)

    In this specific assay the secondary antibody recognises the primary antibody as if it was an antigen. The secondary antibody is quit different because it is actually being conjugated to an enzyme called Urease. Secondary antibody determines how much primary antibody has interacted with the antigen.

  1. Molecular Properties of Enzymes

    into a test tube labeled 1. Add 12 ml of a phosphate buffer to regulate the pH of the reaction and 10 ml of water to equalize the volume of the test tube to that of the volumes of the other test tubes in my previous hypotheses.

  2. This experiment was carried out to characterize an enzyme, -amylase by extracting it from ...

    However, when all the enzymes are saturated with substrate, the rate of reaction will not be further increase even more substrates are added (Taylor et al., 1997). In this experiment, ?-amylase extracted from corn was used. It is an enzyme that hydrolyses long-chained carbohydrate such as starch and glycogen to

  1. Discuss how changes in control of the cell cycle contribute to cancer development ...

    the functional genes that protect cells against uncontrolled cell division, the tumour-suppressor genes. Mutation of these genes does not itself lead to uncontrolled cell growth, but removal of their protective effect means that if oncogenes become activated, cells are more likely to make the progression to the cancerous state.

  2. POMC cell function

    The skin expressions of the POMC peptide receptors are functional in nature. Some of these receptors are MC1R, MC5R, and µ-opiate. The peptides belonging to the MC1R class are found to be more predominant than the other classes. POMC and CRH peptides cause pigmentation of the skin (Slominski, Wortsman, Luger, Paus, & Solomon, July 2000, PP.

  1. The Cytoskeleton - Its Functions and Structure

    However, by themselves they could not provide shape or strength to the cell. The filaments are dependent upon one another and there is a type of protein known as accessory proteins, which link the filaments together and to other cell components.

  2. The Rate of Enzyme Reactions

    - + + + 0:15 - + - - + + + 0:18 - + - - + + + 0:21 - + - - + + + 0:24 - + - - + + + These are the results of the iodine test after the addition of phosphorylase to the solutions.

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