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
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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
vulgaris plants, via the formation of a standard curve prepared using varying concentrations of bovine serum albumin (BSA) solution. Following absorbance readings of the various BSA solutions, they were plotted against their concentrations providing an indirect measure for determining protein concentrations of the plant samples within the assay tubes, and through further calculations the sample protein concentration. The mean protein concentration for the control group was calculated to be 3.34 ± 1.30 mg/mL, while the mean treated group concentration was 2.01 ± 1.26 mg/mL. These results similarly like the chlorophyll results correlate with the literature articles, as a reduced protein content within the Paraquat treated plants can be expected to some extent (Chia et al., 1981). This reduction in protein concentration is the result of those superoxide anions produced by Paraquat, disrupting the chloroplast membranes and allowing for intracellular components including some proteins to leak out, hence the decrease in protein concentration in comparison to the non-treated plants (Qian et al., 2009). A slight outlier may exist within the treated groups protein concentrations as one of the groups provided a negative value for protein concentration which is not valid, but even after exclusion of that data value, results are still supportive of the expected outcome. Though these results support the claim of Paraquat toxicity causing membrane deterioration and leakiness, protein concentration values are rather more purposeful when used to analyze malondialdehyde (MDA) values on per mg of protein
Introduction: The biological membranes are composed of phospholipid bilayers, each phospholipid with hydrophilic heads and hydrophobic tails, and proteins. This arrangement of the proteins and lipids produces a selectively permeable membrane. Many kinds of molecules surround or are contained within
Phospholipids make up most of the cell membrane, in a phospholipid bilayer. Phospholipid molecules form two layers, with the hydrophilic (water loving) head facing the extracellular fluid and the cytosol (intracellular) fluid, and the hydrophobic (not water loving) tails facing one another. The cell membrane is constructed in such a way that it is semipermeable, and allows oxygen, CO2 and lipid soluble molecules through easily, while other molecules like glucose, amino acids, water, and ions cannot pass through quite as easily. That is the meaning behind the chant “some things can pass, others cannot!”.
For this lab 6 male Acheta domesticus were isolated in plastic containers, each was placed in a container that was 5 cm height and had 5.5 cm radius. Each of these containers was punctured with 10-15 minuscule holes for breathing on the lid and 5-8 holes on the sides. Inside of each container a damp paper towel was placed on the bottom and 2 pieces of food were placed on the paper towel. The Acheta domesticus were kept isolated in their personal containers for 7 days. At the end of these 7 days we split the 6 A. domesticus into 3 groups of 2. One of the two was marked with a paint pen, this marked male was the “intruder”. The remaining food was removed from the containers. The “intruder” is then placed into the container that holds the other
The effect of alcohol on
This has been shown by a steady increase in Anthon cyanine leaked out of plant cells as the concentration and temperature increases. The purpose of a cell membrane is to control the transport of substances moving into and out of a cell. The membrane is an extremely thin layer (8 to 10 nanometers (nm)) thick, which is partially permeable. It consists mostly of lipids and proteins.
A major determinant of diffusion in a biological system is membrane permeability. Small, uncharged molecules pass through cellular membranes easily, while most and/or charged molecules cannot pass through the membrane. The movement of water across a selectively permeable membrane, like the plasma membrane
vulgaris were prepared by repeatedly rinsing in distilled water to remove surface betalain (Flinders, 2015). A control group and two treatments were taken, the control was at room temperature (25 degrees Celsius), and the treatments were at 50 degrees Celsius and 80 degrees Celsius. Cubes of B. vulgaris were placed into cuvettes with three ml of distilled water, the treatments were started five minutes apart to ensure each treatment was recorded at the correct time. The light absorbency of each treatment was then recorded using a spectrophotometer set at 540nm, the absorbency for each treatment was checked after 0 minutes, 15 minutes and, 30 minutes in the water baths. Before measuring the light absorbency of each treatment a cuvette with 3 millimetres of distilled water was placed in a spectrophotometer to set it to zero. The absorbency in the solution was measured in arbitrary units (AU), the higher the light absorbency, the higher the plasma membrane permeability. Each treatment was gently swirled before being placed into the spectrophotometer to disperse the colour. Each treatment had three replicates to guarantee an accurate average could be recorded. The results were then collated into tables and
Biological membranes must be semi-permeable to allow the passage of substances in and out of the cell. The semi-permeability allows the passage of substances such as proteins, nutrients, and more to be regulated. Only substances of a particular size can go into the cell and only these certain small substances will be allowed to exit the cell.
The aim of this investigation was to determine the effect of ethanol on the membrane permeability using Beta vulgaris. Beta vulgaris contains red pigments called betalain sequestered in vacuoles. The cell membrane is generally impermeable to betalain as this pigment is relatively large and cannot pass through the membrane by diffusion. (123HelpMe.com, 2015) However, by increasing the permeability of the cell membrane, betalain can leach out of the cell and colour the liquid red. The colour intensity of the solution due to leakage of betalain is proportional to the membrane permeability. To quantify the colour intensity, the light absorbance of the solutions containing a Beta vulgaris cube were measured by a spectrophotometer. These measurements were used to analyse the membrane permeability. (Flinders University, 2015)
All cells contain membranes that are selectively permeable, allowing certain things to pass into and leave out of the cell. The process in which molecules of a substance move from an area of high concentration to areas of low concentration is called Diffusion. Whereas Osmosis is the process in which water crosses membranes from regions of high water concentration to areas with low water concentration. While molecules in diffusion move down a concentration gradient, molecules during osmosis both move down a concentration gradient as well as across it. Both diffusion, and osmosis are types of passive transport, which do not require help.
Introduction: Cell membranes contain many different types of molecules which have different roles in the overall structure of the membrane. Phospholipids form a bilayer, which is the basic structure of the membrane. Their non-polar tails form a barrier to most water soluble substances. Membrane proteins serves as channels for transport of metabolites, some act as enzymes or carriers, while some are receptors. Lastly carbohydrate molecules of the membrane are relatively short-chain polysaccharides, which has multiple functions, for example, cell-cell recognition and acting as receptor sites for chemical signals.
Hypothesis: To investigate the effect of different concentrations of ethanol on the permeability of beetroot cell membranes.
During the twenty-five minutes incubation period, the red beet tissues suffered more stress on its cell membrane at the higher concentration of acetone and methanol than it did at lower concentrations (Figure 1). The data did not consistently show which organic solvent had the greatest effect on cell permeability (Figure 1). The betacyanin absorbance level
Only uncharged, small, polar molecules, (such as water) and hydrophobic molecules, (such as oxygen, carbon dioxide) and lipid-soluble molecules (such as hydrocarbons) can freely pass across the membrane. All ions and large polar molecules (such as glucose) are not permeable to the membrane.