Temperature On The Membrane Permeability Biology Essay


The consequence of assorted temperatures on the membrane permeableness of Beta Vulgaris, more normally known as the ruddy Beta vulgaris, will be investigated in this experiment.

Using seven different samples, each treated to a different temperature, it was possible to compare how temperature effects betacyanin secernment, which is non released under normal conditions. The sum of betacyanin pigments released was determined utilizing light spectrophotometry at a wavelength of 475nm. It was found that an addition in temperature is related to the sum of betacyanin pigments which pass through the membrane. For illustration, at the temperatures 22A°C, 60A°C and 100A°C the values of optical density were 0.0558, 1.

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285 and 1.401 severally. This tendency reinforces the belief that increases in temperature and the sum of betacyanin that is able to go through through the membrane is straight relative because the membrane fluidness additions.


Chemical construction of betanin, the most prevailing betacyanin in Beta Vulgaris ( Sepulveda-Jimenez et al. , 2004 )

Belonging to the Chenopodiaceae household, Beta Vulgaris, or more normally known as the ruddy Beta vulgaris is a root veggie ( Rhodes, 2008 ) , and is red in colour, due chiefly to the presence of betacyanin ( Czapski et al. , 1988 ) . Although there are different types of betacyanins, the chief betacyanin of the ruddy Beta vulgaris is betanin, which is present in high concentrations ( Sepulveda-Jimenez, 2004 ) .

The stableness of Betacyanin is susceptible to a figure of factors, such as: temperature, pH, O, visible radiation, H2O activity and certain metal ions ( Czapski et al. , 1988 ) . These factors account for the sum of betacyanin released, as under normal conditions it can non go through through the selectively permeable plasma membrane.

The plasma membrane of procaryotic cells is a selectively permeable membrane composed of an amphipathic phospholipid bilayer with embedded lipoids, proteins and saccharides. It is described as selectively permeable because certain things can go through through the membrane without being impeded by the phospholipid bilayer, while other substances are wholly blocked from go throughing through the membrane.

These membranes must stay fluid in order to work decently. As temperature decreases a membrane becomes decreasingly permeable until the point where it eventually solidifies, doing the membrane to rupture. However, as temperature additions, the membrane becomes excessively unstable, as the channel and bearer proteins embedded in the membrane start to deform ; doing more substances to leak and go through through the membrane ( Reese et al. , 2011 ) .In this experiment, we observed the consequence that assorted temperatures had on the membrane permeableness of Beta Vulgaris. Since an addition in temperature causes the membrane of procaryotic cells to go more permeable, along with increasing the rate at which molecules diffuse, it is expected that an addition in temperature will do more betacyanin to go through through the membrane. As temperature decreases, the membrane permeableness is besides expected to diminish, until the point where the membrane ruptures, leting the contents to flux freely out of the cell ( Reese et al.

, 2011 ) . The primary aim of this experiment was to look into that consequence that the different temperatures had on the membrane permeableness of Beta Vulgaris.


Six unvarying cylinders of a diameter of 1.0cm and a length of 3.0cm were cut utilizing a cork bore bit. These cylinders of ruddy Beta vulgaris root were placed under running cold H2O and rinsed for about 5 proceedingss. A antecedently frozen ( -20A°C ) sample of Beta vulgaris root was inspected to guarantee a length of 3.

0cm and so thawed to room temperature. These seven samples of Beta vulgaris root were so put in a solution of 10mL of distilled H2O. Then, one solution of Beta Vulgaris was placed in the electric refrigerator at a temperature of 3A°C, the antecedently frozen sample along with another fresh sample were left at room ( 22A°C ) temperature and four samples were placed in H2O baths of 40A°C, 60A°C, 76A°C and 100A°C. These solutions were left to incubate at the trial temperatures for 15 proceedingss.

Once finished their incubation period, the solutions were transferred into fresh cuvettes, pull outing the Beta Vulgaris nucleus in the procedure. Following this, a SpectroVis Plus spectrophotometer by Vernier, utilizing Logger Pro 3.8.4, was used to find the optical density of each sample at 475nm. This procedure was so repeated four times ( Mitchell et al. , 2012 ) .First, to analyse this information, the information was compiled into tabular signifier.

Following this, the average optical density of each intervention was calculated in order to account for the different value of optical density in each test. Using the mean value of optical density, we were so able to cipher the standard divergence for each test. As the information collected was sub dividable, it was deemed to be uninterrupted. Therefore, a line graph was produced with standard divergence mistake bars ( Mitchell et al. , 2012 ) .


Among the different temperatures in which the Beta vulgaris cylinders were treated, fluctuation observed in values of optical density was expected. As seen in Figure 1, the highest optical density value was 1.604, observed at a temperature of -22A°C.

Relatively, the lowest value of 0.0558 was seen at a temperature of 3A°C. Three points of involvement can be seen in the graph. The first occurs in the frozen sample where the optical density is the highest value on the graph. Second, the optical density readings at 3A°C and 22A°C were highly close, 0.

0558 and 0.0588 severally. Finally, the optical density reading at 100A°C does non follow the increasing tendency of optical density value established from temperatures 3A°C to 76A°C.

The value, 1.401, was in fact lower than that of 76A°C ( 1.438 ) but greater than the value observed at 60A°C. It can be noted that a general tendency can be established. As the temperature of Beta Vulgaris increased, the optical density and hence the sum of betacyanin, besides increased. However, the frozen and 100A°C samples did non look to follow this tendency.

Figure 1. The consequence of seven different temperatures on the optical density of Beta Vulgaris, calculated utilizing light spectrophotometry at a wavelength of 475nm.


As the betacyanin pigments present in Beta Vulgaris are hydrophilic and require storage in a vacuole ( Mukundan et al. , 1998 ) , it is important that some kind of intervention be applied to the Beta vulgaris root in order to ease the release of the pigments. In this instance, the temperature was changed in order to do the membrane of the ruddy Beta vulgaris more permeable to the release of betacyanin. However, there are more efficient ways to increase the loss of pigment. As stated by Czapski ( 1998 ) , an addition in pH would hold a greater consequence in the alterations of coloring material properties, while temperature would hold a smaller consequence.

Therefore, if pH had been varied in this experiment instead than the temperature, it would hold been possible to increase the pigment loss by Beta Vulgaris.Variation in the consequences can be the effect of many factors ; such as the age of the Beta vulgaris root sample, nucleuss from different Beta vulgariss were used and the sum of clip the samples were treated at the trial temperatures. The age of the Beta vulgaris would hold played a big function as the proteins in the sample could already be broken down before the experiments are performed, thereby diminishing the sum of betacyanin that could be released. Furthermore, throughout the different tests, nucleuss from different Beta vulgariss were used. These nucleuss contained different concentrations of betacyanin, hence affected the sum of betacyanin which passed through the membrane. Finally, the sum of clip the samples were treated was besides an of import factor. These solutions were supposed to be treated for 15 proceedingss ; nevertheless, if left under intervention for more clip, the sum of betacyanin secreted by the Beta Vulgaris would increase.It can be concluded that as temperature additions above 3A°C, the sum of pigment, betacyanin, which was ab initio unable to go through through the membrane, released is relative to the addition in temperature.

This is caused by the membrane going excessively unstable while the channel and bearer proteins embedded in the membrane start to deform ( Reese et al. , 2011 ) , doing escape through the membrane. In another similar experiment, the research workers concluded that the sum of betacyanin released was relative to an addition in temperature ( Thimmaraju et al. , 2002 ) ; nevertheless, merely the alteration between 40A°C, 45A°C and 50A°C Beta Vulgaris samples was studied. In the instance of the frozen sample, the consequence can be explained in footings of the cell membrane ; when frozen, the membrane of the cell ruptures ( Roquebert and Bury, 1993 ) .

This consequences in the betacyanin passing through the membrane with comparative easiness.This experiment established the general tendency that as temperature additions, the sum of betacyanin which passes through the membrane besides increases. Although, two points of involvement occur at -22A°C and 100A°C, which did non follow this tendency. At -22A°C the membrane ruptured ( Roquebert and Bury, 1993 ) , which allows the pigment to be released freely.

While at 100A°C a worsening tendency is established as the samples lost their viability ( Thimmaraju et al. , 2002 ) . Further research in the country of the membrane permeableness of Beta Vulgaris should concentrate on the effects that pH has on the sum of betacyanin released, comparing these consequences to those which have undergone temperature interventions.

Literature Cited

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, & A ; Grajek, W. ( 1998 ) . Analysis of biodenitrification conditions of ruddy Beta vulgaris juice utilizing the response surface method. Journal of Agricultural and Food Chemistry, 46 ( 11 ) , 4702-4705Mitchell, G, Roe, G. , Beaulieu, G.

, and Creasey, D. , Brand, D. , Lisson, P. , Marx R.

, and Metacalfe, R. ( 2012 ) . Biology 190A Laboratory Manual. Department of Biology, University of Victoria, Victoria, B.C.

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pH-mediated release of betalains from transformed root civilizations of beta vulgaris L. Applied Microbiology and Biotechnology, 50 ( 2 ) , 241-245.Reece, J. B. , Urry, L. A. , Cain, M.

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San Francisco, California: Benjamin Cummings.Roquebert, M. F. , & A ; Bury, E. ( 1993 ) . Consequence of freeze and dissolving on cell membranes of Lentinus edodes, the Chinese black mushroom mushroom. World Journal of Microbiology and Biotechnology, 9 ( 6 ) , 641-647. Department of the Interior: 10.

1007/BF00369571Rhodes, D. ( 2008, January ) . HORT410 – Vegetable Crops.A Horticulture and Landscape Architecture – Purdue University.

RetrievedA OctoberA 12, 2012, from hypertext transfer protocol: //www.hort.purdue.edu/rhodcv/hort410/spina/sp00001.htmSepulveda-Jimenez, G.

, Rueda-Benitez, P. , Porta, H. , & A ; Rocha-Sosa, M. ( 2004 ) .

Betacyanin synthesis in ruddy Beta vulgaris ( beta vulgaris ) leaves induced by injuring and bacterial infiltration is preceded by an oxidative explosion. Physiological and Molecular Plant Pathology, 64 ( 3 ) , 125-133.Thimmaraju, R. , Bhagyalakshmi, N. , Narayan, M. S. , & A ; Ravishankar, G.

A. ( 2003 ) . Dynamicss of pigment release from haired root civilizations of beta vulgaris under the influence of pH, sonication, temperature and O emphasis. Process Biochemistry, 38 ( 7 ) , 1069-1076.


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