Cell Membrane and Temperature - Lab Report Example

Cell Membrane and Temperature Introduction The cell membrane is an essential component of the structure of the cell and isolates the cell from its external environment. Yet nutrients, signalling molecules and waste products need to pass in and out of a cell through the plasma membrane. The structure of the plasma membrane assists in the controlled and selective ingress and egress of ions and molecules from and to the external environment of the cell (Nester et al, 2004). The structure of the cell membrane is such that it acts as a semi-permeable barrier between the internal environment of the cell and the external environment of the cell, which assumes functional significance for the cell membrane (Kelly & McCorry, 2004). The semi-permeable cell membrane allows for free movement of non-water soluble materials in an out of the cell, but curtails the movement of water soluble materials (Sherwood, 2005). Diffusion, facilitated diffusion and active transportation are the means by which the selective action of movement of water soluble materials in and out of cells through the cell membrane occurs (Gartner, Hiatt & Strum, 2006). Beetroot is a vegetable that has red pigments called batalins. Batalins are located within the cell vacuole of the sells of the beetroot. Under normal conditions these water soluble pigments cannot pass through the cell membranes and hence are retained within the cells. However, when beetroot is cooked in water these pigments are found to leak out of the beetroot cells. The cell membrane thus demonstrates a characteristic of being affected by temperature. Aim The aim of this practical test carried out is to examine the effect of temperature on cell membranes by studying the affect of temperature on the semi-permeability of the cell membranes of beetroot, using transportation of batalins out of cells as the means for the study. Materials and Apparatus 1. Cork Borer – Size 4. 2. White Tile. 3. Sharp Knife 4. Measuring Scale. 5. Water Baths maintained at temperatures of 0, 10, 20, 30, 40, 50, 60 and 70 degrees Celsius. 6. Plastic Beaker of 250cc approximate capacity. 7. Crushed Ice – 1000gms. 8. Boiling Tubes – 8 nos. 9. Thermometers – 8 nos. (One per bath). 10. Stop Clock. 11. Distilled Water – 1 (500ml) 12. Pipette – for measuring 2cc. 13. Calorimeter and 14. Cuvettes – 8 nos. 15. Beetroot – 1 medium size. Procedure Using the size 4 cork borer, the medium sized beetroot was made into sections. Theses sections were placed in the plastic beaker containing distilled water. This beaker was left undisturbed overnight to wash away any dye that resulted from the sectioning of the beetroot. The next day the sections of the beetroot were taken from the beaker and placed on the white tile. Using the sharp knife and the measurement scale eight 1 cm long slices of beetroot were cut. Eight water baths were set up at different temperatures. The different temperatures in the water baths were maintained in the water baths with the help of the addition of hot water or crushed ice. Thermometers were placed in the water baths to assist in reading the temperatures of the water baths. Eight boiling tubes containing 5cc of distilled water were suitably labelled as 0, 10, 20, 30, 40, 50, 60 and 70 decrees Celsius and placed one in the appropriate water baths maintained at these different temperatures. The boiling tubes were kept in the water baths for five minutes till the required temperature was achieved, which was measured with the help of the thermometers. Then one section of the beetroot was placed in each of the boiling tubes and the boiling tubes maintained in the water baths for a period of thirty minutes, after which they were removed from the water baths. The beetroot sections were then removed from the test tubes and the shaken well to disperse the dye. Then 2cc of the dye solution was from each of the boiling tunes were put in eight cuvettes and marked appropriately. The calorimeter was switched on and set to read the value for absorbency. Adjustments were made in the calorimeter so that the reading of absorbency was zero for clear water. The filter was set and dialled to the blue/green filter. Each of the calorimeter cuvettes containing the dye solution was placed in the calorimeter and readings were recorded against each of the selected temperature parameters. Colour Observation Red colouring was observed in each of the cuvettes. The darkness of the red colouring increased with rise in temperature. Table of Results Dye solution (degrees c ) 0 10 20 30 40 50 60 70 Calorimeter readings 0.15 0.12 0.13 0.15 0.2 0.39 2.00 2.00 Discussion At the temperature of ten degrees Celsius there was minimal transportation of batalin outside of the beetroot cells, which remained almost unaltered at the temperature of twenty degrees Celsius. Slight increase in the transportation of batalin outside of the cell is noticed at temperatures of 0, 30 and 40 degrees Celsius. There is a marked increase of nearly fifty percent in the increase of batalin transportation outside of the cell membrane. At sixty degrees Celsius the transportation of batalin pigment outside of the cell membrane drastically enhances to more than five times that at forty degrees Celsius. There is no change in the levels of batalin transportation at seventy degrees Celsius in comparison to sixty degrees Celsius. There is a tendency for rise in the transportation of batalin pigment outside of the cell membrane at fifty degrees Celsius and a very marked increase at sixty degrees Celsius, which remains unchanged at seventy degrees Celsius. These findings show that at temperatures of forty degrees Celsius and less the semi-permeability function of the cell membrane in maintaining control of the movement of water soluble materials in and out of the cell remains unaffected by rise in temperature or the function of the cell membrane remains normal, whereby the semi-permeability of the cell membrane prevents the egress of water soluble batalin pigment out of the cell environment (Kelly & McCorry, 2004). At fifty degrees Celsius the semi-permeability of the cell membrane starts to get compromised allowing greater egress of the batalin pigment to the outside of the cell environment. From sixty degrees Celsius onwards the semi-permeability and function of the cell membrane totally compromised, allowing for the free diffusion of the batalin pigment to the outside of the cell environment (Sherwood, 2005). Temperature has an impact on the movement of materials through the cell membrane. Increase in temperature creates more kinetic energy among the fatty acid chains in the cell membranes. This causes increases movement among the fatty acid chains, making the membrane more fluid making for reducing control over the control of materials that move in and out of the cell membrane. This is the reason for the observations of increased flow of the batalin pigment out through the cell membranes with increase in temperature. Below four degrees water is less dense than water at higher temperatures. The lowering of density increases the volume of water in the cell stretching the cell membrane and causing greater egress of materials through the cell membrane, as demonstrated in the observation of the increased egress of the batalin pigment at zero degrees Celsius. (Gartner, Hiatt & Strum, 2006). This experiment is to study the effect of temperature on the cell membrane. In its methodology, small slices of beetroot have been used to compare the. These small slices of beetroot do not contain the same number of cells in each. The outflow of batalin pigment is affected by the number of cells present in each of the slices. This means that were the experiment to be repeated, it is not necessary that the observations remain the same, affecting the reliability of the results. This is a study of the function of a component in the structure of the cell. Hence the study should be conducted at cell level. To improve the methodology of the experiment, it is suggested that the same experiment be conducted, but instead of a comparison between eight measured slices of beetroot at different set temperature the same be done using the same number of beetroot cells at set different temperatures. In other words the methodology of the experiment has to be scaled down from the macro level to the micro level. . Literary References Gartner, P. L., Hiatt, L. J. & Strum, M. J. 2006, BRS Cell Biology and Histology, Lippincott Williams & Wilkins, Philadelphia, Pennsylvania, pp. 4-7. Kelly, L. & McCorry, K. L. 2004, Essentials of Human Physiology for Pharmacy: An Integrated Approach, CRC Press, Boca Raton, Florida, pp.7-8. Nestor, W. E., Anderson, G. D., Roberts Jr., E. C., Pearsall, N. N. & Hurley, D. 2004, Microbiology: A Human Perspective, Fourth Edition, McGraw Hill Higher Education, Boston: pp. 70-73. Sherwood, L. (2005), Fundamentals of Physiology: A Human Perspective, Thomson Brooks and Cole, Belmont, California, pp.53-58. Read More