Effect of Temperature on Permeability of Cell Membrane

Betalain are the red coloured pigment which happens in the vacuoles of the beetroot cell, a membrane called the tonoplast is what surrounds each vacuole. The leakage of the beetroot red coloured pigment which is the Betalain, out of the cell will determine how permeable the cell membrane is at a certain time. As the water gets darker by the dye more light is

4) The Sucrose molecules cannot pass through the plasma membrane, but osmosis can still occur. So, the permeability of the potato’s cytoplasm only applies to the H2O molecules.

Change in pH concentrations increases permeability of beetroot (‎Beta vulgaris) cell membranes indicated through color intensity using the spectrophotometer

7. Explain how incubation plant tissues in a series of dilutions of sucrose can give an

The purpose of this experiment was to alter the cell membrane of the beets, in a given fashion, so that we can test how much betacyanin was able to cross the cell membrane of the beet through various treatment. In which after we would test the absorbance level of each treatment, run it through excel and observe which treatment was most effective at getting betacyanin through the cell membrane more.

The reasoning behind this experiment is the examine whether the rate of osmosis is changed due to a change in temperature. It was hypothesized that the rate of osmosis will increase as the temperature of the sucrose is increased. The rate of osmosis was tested by using the different jars full of different temperate water and testing how high the water rose on an osmometer over a span of 20 minutes. An osmometer is a tool used to measure rates of osmosis. The different temperatures tested on a sucrose solution were 5 degrees Celsius, 20 degrees Celsius, and 37 degrees Celsius. Rates of osmosis were higher in the hot water than in the cold water and control. The results showed that the rate of osmosis increased as the temperature increased, henceforth the hypothesis was supported. In conclusion, the experiment showed how changes in temperature affect the rate of osmosis.

Thus it forms holes, disrupting the membrane of the beetroot core which essentially prevents the betacyanin pigment from leaving the cell. Also, when exposed under heat, the cholesterol, glycolipids and phospholipids expand, putting pressure on the membrane from inside. The lipid part of the membrane will become liquid, making it open to leakage. The proteins in the membrane will denature, increasing the permeability in the surface. The combination of vibrating molecules and a denaturing membrane would disrupt the organized structure of the membrane. And eventually with a disrupted membrane, betacyanin pigment in the innermost compartment will leak out.

Osmosis is defined as the tendency of water to flow through a semipermeable membrane to the side with a lower solute concentration. Water potential can be explained by solutes in a solution. The more positive a number is more likely it will lose water. Therefore should water potential be negative the cell the less likely it will lose water. In using potatoes the effects of the molarity of sucrose on the turgidity of plant cells. According to Clemson University, the average molarity of a White potato is between .24 M and .31 M when submerged in a sorbitol solution. This experiment was conducted with the purpose of explaining the relationship found between the mass in plants when put into varying concentrations of sucrose solutions. Should the potatoes be placed in a solution that contains 0.2M or .4M of sucrose solution it will be hypotonic and gain mass or if placed in .6M< it will be hypertonic and lose mass instead. Controlled Variables in this lab were: Composition of plastic cups, Brand of Russet Potatoes, Brand of Sweet Potatoes and the Temperature of the room. For independent variable that caused the results recorded it was the different Sucrose concentrations (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M). The dependent variable was the percentage change from the initial weighs to the final. The cup with .4 molarity was the closest to an isotonic solution and was used as the control group for the lab. Water potential is the free energy per mole of water. It is

out the potato and dry it to ensure excess water is not added to the

In order to observe the effects of the various temperature manipulations, the test was performed six times at various temperatures. For this test the beets were placed into separate non permeable plastic bags and were then completely submerged in several water baths set at the temperatures of -25ºC, 5ºC, 25ºC, 45ºC, 65ºC and 85ºC for 2 minutes each. Once the plastic bags were removed from the baths, the beet discs themselves were removed and then placed into different test tubes of water with the temperatures set at room temperature for fifteen minutes. The test tubes underwent vigorous spinning by a vortex machine every five minutes to allow for maximum leakage results per beet disk manipulation. Once the beets sat in the water for fifteen minutes, 2mL of the surrounding solvent was poured into a cuvette to be measured with the spectrophotometer.

Hence, the hypothesis was refuted. Based on a previous experiment conducted by Thimmaraju R et al. (2002), the release of betalain increases as the temperature of the solution increases. Furthermore, as stated earlier in the introduction, the membrane permeability will decrease if the temperature decreases (Martin C et al, 1976). These previous experimental observations did not occur in this investigation and could be due to the random and systematic errors that

Tonoplast is quite large and typically contains water. In beetroot plants, this membrane-bound vacuole (Tonoplast) also contains a water soluble red pigment, betacyanin, which is what gives beetroot its colour. (Bjarnadottir, 2014) Due to the fact that the pigment is water soluble, not lipid soluble, it remains in the vacuole when the cells are healthy. However if the integrity of a membrane is disturbed, then the contents of the vacuole will release into the surrounding environment. (Bjarnadottir, 2014)This usually means the cell is dead. If beetroot membranes are damaged-- red pigment will leak out into the surrounding environment. Although these cells are not the same as the dendrites they can still act as a model for a cellular damage analysis. This is why I have chosen beetroot to serve as my ‘biological membrane’. As well as this beetroot contains thiamine. (Bjarnadottir,

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

A eukaryotic cell not only has a plasma membrane as its external boundary, but it also has a variety of membranes that divide its interior into discrete partitions, separating processes and cell mechanisms (National Center for Biotechnology Information, 2012). The complex and varied design of the phospholipid bilayer allows the membrane to serve the variety of specific functions required by different types of cells. Moreover, one of the most significant properties of membranes is selective permeability; permitting the passage and movement of ions and molecules to pass freely through the membrane, but excludes others from doing so (Ek-Vitorin and Burt, 2013). One type of membrane-bound vacuole is found in plant cells, the tonoplast is quite large and contains water (Dee, 2000). Within Beta vulgaris cells, the membrane bound vacuole also contains a red, water soluble pigment, known as betacyanin, that provides the beetroot with its characteristic colour (Nottingham, 2004). As the pigment is water soluble, it remains in the vacuole of the cell, however if the integrity of the membrane is disrupted (through direct chemical damage, channel damage, injury via viruses, etc.) the contents of the vacuole will diffuse out into the surrounding environment (Andrews, Almeida and Corrotte, 2014). Through practical analysis, the effects of various chemicals on membrane permeability in B.vulgaris was observed through the utilization of various concentrations of ethanol – 0%, 35% and 70%

When put under stress, at some point materials begin to decline and perform poorly. Cell membranes are no different. The specific design and structure of plasma membranes allows for the regular function of cells through transportation, facilitating reactions, and several other tasks carried out by the cell membrane and endomembrane system. When put under physical or chemical stress, however, the plasma membrane begins to falter and will eventually become unable to perform its tasks, which are necessary to cell life. Using beet root tissue, the relationship between membrane performance and temperature was tested. 3 samples of beet were prepared and placed in a 50% methanol solution and exposed to temperatures above, below, and at room temperature. The membrane’s performance in repelling an unwanted solution in adverse conditions was measured by the amount of damaged membranes, which resulted in increases in released pigments. This lab’s hypothesis is: varying temperature will have an inverse effect on the membrane performance. The membrane will perform more poorly under increased heat than increased cold, but both changes in temperature will negatively affect the performance of the membrane. This will be measured by amount of light reflected by the spectrophotometer, reflecting how much pigment was given off, and therefore how many membranes were compromised. The independent variable is the temperature the sample is put through, and the controlled variables