MATERIAL AND METHODS Stability of cell membrane using pHF or the lab experiment for testing the stability of beet cell membranes using pH, many materials were used as follows. Obtaining a beet we punch out cores, using a cork borer. After washing the cores we put each one inside a separate test tube, and added a different pH solution in each one. After 3 minutes in these exposure solutions, we took the beet out with a dissecting needle.
Then transferred each beet to a separate test tube containing deionized water. After 20 minutes in these diffusion solutions, we took the beets out with a dissecting needle and discard it. We then stirred each solution in the test tube with a stirring rod, and transferred it to a cuvette. A spectrophotometer was then calibrated, and used to measure the absorbance of each exposure solution, and diffusion solution. Membrane Damage For the lab experiment for Membrane Damage, we tested the extract pigment and diluted it. When the pH solutions are added, this will cause it to be in a range of absorbance.
We used materials as follows. Obtaining a beet we proceeded to cut small individual cubes. We then rinse each cube to remove any damaged pigments with deionized water. Using a blender, we blend the beets with 15 mL of pH 7 DI water. After blending we used cheesecloth to separate the liquid from the solids for easier centrifuge process. Then we put the liquid beet into a centrifuge tube and centrifuge it for 5 minutes at 2500 rpm.
We then remove the supernatant into a beaker, and discarded the sediment. Using a 1: 4 ratio mixture of the supernatant and deionized water, we made a stock solution. We then tested the stock solution's absorbance with a spectrophotometer, and place 1 mL of the solution into separate test tubes. Next we added an additional 4 mL of pH solutions in the 2-11 range into each test tube. After mixing, we tested the absorbance for each solution using a spectrophotometer. Mixing the Diffusion and Exposure Solution For the lab experiment of mixing the diffusion and exposure solution, we are going to test if the pigment is released in the exposure solution.
We used materials as follows: Obtaining a beet, we punched out 2 cm long beets using a cork borer. Then we wash the beets in running water, after that we prepared 10 test tubes each containing different pH solution. Next we put the beets into each test tube for 3 minutes, making an exposure solution. We prepared 10 more test tubes each containing 8 mL of deionized water.
After the 3 minutes, using a dissecting needle, we transferred the beets from the exposure solution into the deionized water test tubes for 20 minutes making a diffusion solution. We then stirred each exposure solution in the test tube, and transferred them to a cuvette. Using a spectrophotometer set at 535 nm, we calibrated each exposure solution and found its absorbance. We proceeded to do the same with the diffusion solution.
After the calibration, we mixed the exposure and diffusion solutions that used the same beet together, for each test tube. Using a cuvette, we calibrated each mix solution to find its absorbance. Temperatures affecting Plasma Membrane For this lab experiment we are testing to see extreme temperature can damage a plasma membrane. Obtaining a beet, we punched out 10 2 cm long beets using a cork borer. Then we wash the beets in running water. We placed two cores into separate centrifuge tubes for freezing.
One was freeze at -70 C, and the other at -20 C for 5 minutes. After taking it out we diffused each core with deionized water for 20 minutes. We proceeded to place another core into a 4 C refrigerator for 5 minutes, and diffused it with deionized water for 20 minutes. Using a pre-heated boiling water bath of 50 C, 60 C, and 100 C, we added 4 mL of each bath into separate test tubes containing a core. Then heated it for 5 minutes and remove the core to allow diffusion in deionized water for 20 minutes.
Using a spectrophotometer set at 535 nm, we calibrated each diffusion solution to measure the absorbance. Deionized water as the solvent blank. Organic Solvents affecting Plasma Membrane For this lab experiment we are testing to see if organic solvents can damage a plasma membrane. Obtaining a beet, we punched out 2 cm cores using a cork borer. We then made 10 dilutions of ethanol, starting at 100% and decreasing by 10% for each one in a test tube.
Next the individual cores are placed into separate test tubes, and add each of the 10 dilutions into each test tube. Allowing the core to expose and diffuse for 5 minutes. After diffusion, we used a spectrophotometer set at 535 nm to measure the absorbance for each solution. The solvent blank was the same dilution as the solvent for each test tube..