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Beta Vulgaris Lab Report

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The effect of ethanol concentration on the membrane permeability of Beta Vulgaris
Introduction
Characterised by their phospholipid bilayer, membranes are the structures of cells that regulate the entry and exit of materials to ensure that it’s internal and external environment vary (Lecornu & Diercks, 2013). The ease with which materials penetrate this membrane refers to its permeability, which can alter depending on the substance introduced (Patra et al, 2006). Hence, cell membranes are selectively permeable, with small and uncharged molecules penetrating with most ease (Lecornu & Diercks, 2013).
Ethanol is a non-polar and uncharged alcohol, when at high concentrations, will destroy the lipid bilayer barrier of membranes and increase ion …show more content…

If a larger range of ethanol concentrations were trialled than Kalant’s (1971) claim could be tested for accuracy, and a trend could be determined to reliably support or reject the hypothesis. Moreover, the ethanol concentrations used differed significantly, thus it was difficult to identify random errors and establish an accurate trend from which the data could be analysed. Many aspects also limited the scientific scrutiny of the results. For example, the B. Vulgaris cubes were rinsed and immersed in distilled water before the experiment to remove surface betalain. Depending on the time periods these occurred, the water could have hydrated and increased the membrane permeability of the cubes to varying degrees (Disalvo et al, 2008). Consequently, these would skew the results, as they can no longer be attributed to the ethanol concentration. Alternatively, depending on how well the cubes were rinsed, some surface betalain may have adhered and further coloured the solution, such as that for Treatment 1. Additionally, the time in which the B. Vulgaris was immersed in the treatments may have not been long enough for the betalain to leach completely in Treatment 2, but enough for Treatment 1 to leach it’s maximum betalain, resulting in its higher membrane permeability. Moreover, only the spectrophotometer was used to indicate membrane permeability, which could have limited the data, as if the values were incorrect due to improper calibration of the machine, no other data was available to analyse and compare permeability. The treatment solutions were also not personally prepared and in bulk, hence, the vials may have been incorrectly labelled, resulting in the unexpected results in Figure

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