Investigating the Effect of Temperature on the Permeability of Membranes

This lab was performed to test the permeability of the cell membrane of a beet using various and extreme temperatures (high and low). The prediction of this lab is testing how much stress the cell membrane can withstand under different polarities and strengths of bonds using our understanding of the fluid-mosaic model. A spectrophotometer was used to calculate the absorbance of each variable after the beet was placed in each environment. When the lab was completed, the data stated that under each different reactant and condition the cell membrane showed multiple changes in tolerability of the beets.

Students will label 3 test tubes hot, cold, and room temperature and place potato cub (3X3X3 cm)

Prediction: By exposing a membrane to a solvent, ethanol, it will increase its permeability. So the higher the concentration of the solvent, the more permeable the membrane will be. But if the concentration of the ethanol is beyond a certain limit, it may break down the cell membrane to the point where there is in fact no overall effect as the ethanol would disturb the lipids in the membrane.

For problems requiring computations, please ensure that your Excel file includes the associated cell computations and/or statistics output; this information is needed in order to receive full credit on these

items presently in solid form in the lab kit or purchased separately for this laboratory

1. What was the purpose of using water as a sample in some of the tests performed in the lab? (2 points) to have a control.

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 Effect of Temperature on the Permeability of Beetroot Membrane Analysis The graph shows the colorimeter readings increase as the temperature increases, they increase by the most at higher temperatures. This is shown by a smooth curve. This means that the beetroot samples release more dye at higher temperatures.

7. The data set for this problem can be found through the Pearson Materials in the Student Textbook Resource Access link,

An increase in temperature increases the kinetic energy of betalain molecules thus increasing rate of diffusion of the red pigment from the cytoplasm into the distilled water. The denatured proteins and an increase in the fluidity of the phospholipid causes the substance contained in the membrane to leak out.

The cell membrane plays multiple important roles regarding the overall function of the cell such as separating the intracellular parts of the cell from the extracellular environment. One of the main functions of the cell membrane is to regulate the transport of molecules in and out of the cell (Maderin 2009). The cell membrane itself is actually made up of a lipid bilayer which is broken down even more to fatty acid chains, proteins, and cholesterol. The lipids of the bilayer are aphipathic, which means that they have hydrophilic polar heads pointing out and the hydrophobic portion forming the core (Gwen 2001). Within the bilayer, proteins are embedded. These proteins may sometimes pass through the bilayer, or they may be inserted at the cytoplasmic or exterior face. The fluid characteristics of the cell membrane come from this lipid bilayer. The phospholipid bilayer also forms sacks within the plant cell. One surrounds the whole cell, which creates the cell membrane, while another sack surrounds the vacuole (Howard 2003). The special membrane that surrounds the vacuole is known as the tonoplast membrane (Peter 2004). Within the vacuole is a molecule known as betacaynin. Betacyanin is any one type of a group of pigments. It is a nitrogen containing glycosylated compound that is responsible for the red color in the beta vulgaris or beetroot (Encyclopedia 2004).The Betacyanin is stored within the vacuole of the plant cell. At normal temperatures the betacyanin remains within

al the stalk and root if you want to avoid getting lots of red dye in

Consequently, membrane permeability gets distorted, due to progressive release of lipopolysaccharide molecules and membrane proteins.

Laboratory ABC uses both glass pipettes (1mL to 5mL) and disposable plastic pipette tips- yellow (20μL), blue (1000μL) and white (5mL). Glass pipettes and white pipette tips are currently washed and reused. Blue and yellow tips are discarded.

The objective and the main purpose of this experiment were to determine the effects of temperature on membrane permeability. Physical treatment on membrane permeability with its effects on the basis of the known chemical composition of the membrane was investigated. The major result of this experiment was the maximum membrane permeability was determined by the maximum absorbance value. Also the membrane becomes more permeable at higher temperature, which was the expected result considering the fact that the protein denatured at higher temperature and phospholipid became less stable because its shape and structure changed. As figure.1 states the result of this experiment as temperature increases, the mean absorbance value increases as well (Reece et al., 2014).