The Effect of Temperature on Membrane

Originally, the absorbance measured for samples in –5°C and 70°C were 1.700 and 0.845; the concentrations were 425 μm and 180 μm respectively. However, because both of these absorbance readings were greater than the highest absorbance value in our standard curve (Figure 1), a calculation of diluted concentration for these two samples was necessary. Therefore, using the formula Cu = Cd/D where Cu = concentration of undiluted (original) sample, Cd = concentration of diluted sample and D = dilution (which is 1/5 in this experiment), we calculated that the diluted concentration for the sample in 5°C is 85 μm and for the sample in 70°C is 36 μm. As we inserted these data on the graph (Figure 2), concentration of betacyanin for samples in –5°C and 70°C still dominate in comparison to others. This sudden increase of concentration allowed us to understand that the tonoplast membrane is easier to be damage in extreme temperature.

Aim: To investigate how effect of Detergent Concentration (cont.) has on Membrane permeability of Beetroot cells. Hypothesis: I predict that as detergent concentration increases, the solution will become less clear, plus mass increases. The increases in mass will indicate that the water potential of the Beetroot cell is lower than that of the surrounding sucrose solution. The Beetroot discs will become flaccid and decrease in mass if the water potential of the surrounding solution is lower than the water potential inside the beetroot cell.

Therefore, more of the red pigment in the beetroot would leak as the lipids control the substances that enter and leave the cell membrane.

The cell membrane (Plasma membrane) functions to provide cell support, cell stability and control entry and exit of materials from the cell. This study was conducted to test the effects of environmental conditions such as the on beet root cell membrane (Beta vulgaris). Five trials using varied pH concentrations were tested and absorbance rates were monitored. The experimental results showed that the protein function decreased sequentially when the pH decreased. This allowed the betacyanin dye to leak out which created the color that was needed to determine the intensity and therefore the effect of the circumstances. This supported the hypothesis that the more acidic or basic the environmental condition around the beet cell, the more permeable the, membrane indicated by color intensity. Pigment leakage in the solution was analyzed by using a spectrophotometer.

4. Temperature will be kept consistent at room temperature - All tested will be done in the Biology laboratory with the windows shut to make sure the temperature will not change during the tests. The higher the temperature, the shorter the time will be needed for the chemical reactions to happen and phenolphthalein to turn from pink to colourless.

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.

Extrinsic proteins recognise and bind on specific molecules, eg. hormones. Membranes can also be embedded in the inner membrane The reason why the membrane structure breaks down at higher temperatures is because the proteins are not very stable and break down with heat, called denaturing. An enzyme denatures because the heat changes the shape of the active site o the substrate can not fit into it. Enzymes are always denaturing, but at higher temperatures this occurs more rapidly.

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.

15) Obtain the boiled chloroplast suspension, mix, and transfer 3 drops to cuvette 4. Immediately cover and mix cuvette 4. Insert it into the spectrophotometer's sample holder, read the percentage transmittance, and record it in Table 4.4. Replace cuvette 4 into the incubation test tube rack. Take and record additional readings at 5, 10, and 15 minutes. Mix the cuvette's contents just prior to each readings. Remember to use cuvtte 1 occasionally to check and adjust the spectrophotometer to 100% transmittance.

The cell membrane consists of eight distinctive parts that each have their own unique structure and function. The phospholipid bilayer is an integral part of the cell membrane because it is the external layer of the cell membrane and composes the barriers that isolate the internal cell components and organelles from the extracellular environment. It is composed of a series of phospholipids that have a hydrophobic region and a hydrophilic region. These regions are composed of the hydrophilic heads and the hydrophobic tails of the phospholipids, this organization of the polar heads and nonpolar tails allows the heads of the cell to form hydrogen bonds with water molecules while the tails are able to avoid water. The phospholipid bilayer also has many important functions within the cell, it gives the cell shape, provides protection, and it is selectively permeable which allows it to only let very specific molecules pass through its surface. The phospholipid bilayer is an important structure because it prevents harmful and unwanted molecules from entering the cell and isolates organelles which helps to maintain the internal environmental homeostasis of the cell.

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.

In this lab, neutral red was used as a pH indicator. The color changes from yellow to red in a basic solution to an acidic solution. The neutral red dye was applied to Saccharomyces Cerevisiae. When the S. Cerevisiae cells come in contact with the neutral red dye, the dye gets to the cell by crossing the cell membrane. The cell membrane is the outer surface of the cell that functions as a barrier. The outside of the cell membrane is made of lipid and membrane proteins (Hardin, 2012). It is selectively permeable, which means only select ions and molecules can pass through it by transport. Membrane transport can be actively or passively moving a substance from side of the membrane to another (Hardin, 2012). Passive transport does not require energy to move molecules across the cell membrane. Diffusion is a form of passive transport that moves molecules across the membrane from an area of higher concentration to an area of lower concentration. Osmosis, diffusion, and facilitated diffusion are all examples of passive transport. Active transport requires energy to move molecules across the membrane from areas of lower concentration to higher concentration. It requires energy because it pushes sodium ions (Na+) and potassium ions (K+) (Hardin, 2012). When the dye entered the cell, it also showed its location. Sodium azide (Na+N3-) is a metabolic inhibitor that blocks the flow of electrons along

Throughout the experiment, the color of the solution remained colorless. At first, the temperature jumped to 60°C and the liquid of the lower boiling point started to evaporate, condense, and collect in the Falcon tube. Through the first and second receiving tube, the temperature stayed constant at 60°C. However, once I switched to the third receiving tube, the

Time - Time is an important factor. When leaving the beetroot in the test tubes it must be ensured that they are in the water for exactly 20 minutes each. This will make sure that the same period of time is given for dye leakage to occur. To control this, putting the beetroot into each test tube two minutes apart will give enough time for them to be removed before the next test tube is ready to have its contents removed.

A membrane is a thin film of porous material that allows water molecules to pass through it, but simultaneously prevents the passage of larger and undesirable molecules such as viruses, bacteria, metals, and salts. Membranes are made from a wide variety of materials such as polymeric materials that include cellulose, acetate, and nylon, and non-polymeric materials such as ceramics, metals and composites. Synthetic membranes are the most widely used membranes in the desalination process and their use is growing at a rate of 5-10% annually.