Investigating the effect of temperature on plant cell membranes
The purpose of this activity is:
• to practise experimental and investigative skills • to investigate the effect of temperature on cell membrane structures
Procedure
SAFETY: Always carry scalpels clasped to a tile and with the tip pointing away from you.
Beetroot cells contain pigments called betalains that give the tissue its dark purple-red colour. The pigment is contained in the cell vacuole.
Investigation
a. Collect 3 or 4 beetroot cores from the beaker provided. Cut each core into 2 cm sections until you have enough for one core for each temperature of water bath that you will be using. Put your 2 cm sections into a test tube with plenty of
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This means that the vacuole contents will more readily leak into the water in the test tube. The higher the temperature, the greater the disruption to the plasma membranes and the more pigment will leak out in 30 minutes.
2. The factors controlled in this test are the ones that are the same from one group to another – the size of the beetroot cores (their surface area and volume), the advance treatment of the beetroot cores, the volume of water in the test tubes, the pre-heating (or chilling) of the water in the test tubes using the water baths, the length of time the cores spend in the water baths, the treatment of the cores after heating. The experiment could be made more reliable by using more samples of beetroot, and by maintaining the temperature with thermostatically-controlled water baths.
3. The higher the temperature, the greater the amount of pigment released from the
There are many procedures during this lab and many materials needed for an accurate analysis of data. First, fill a 100 mL graduated cylinder with 50 mL of water. Add 25 germinating peas and determine the amount of water that is displaced. Record this volume of the 25 germinating peas, then remove the peas and put those peas on a paper towel. They will be used for the first respirometer. Next, refill the graduated cylinder with 50 mL of water and add 25 non-germinating peas to it. Add glass beads to the graduated cylinder until the volume is the same to that of germinating peas. Remove the beads and peas and put on a paper towel. They will be used in respirometer 2. Now, the graduated cylinder was filled once again, determine how many glass beads will be require to reach the same volume of the germinating peas. Remove the beads and they will be used in respirometer 3. Then repeat the procedures used above to prepare a second set of germinating peas, dry peas and beads, and beads to be used in respirometers 4,5,and 6, the only difference is the temperature of the water.
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.
In tube 3, the water was at 40. This is still warm but not the color was not nearly as intense as the previous tube. The next tube charted was tube number 4. The beet was subjected to a temperature of only 22°c. That temperature I would chart as “room temperature”. I found that the least amount of dye was leaked from the beet. For the cold methods I concluded that the amount of betacyanin that escaped from the cell membrane was intense, like the hot treatment results. I concluded that it didn’t have to be hot temperature stress to release betacyanin. Tube number 5 was placed into the refrigerator and the level of dye that permeated the water was charted at a 6. Tube 6 was placed in the freezer and was documented at a level of color intensity of a ten. Also, when the tube was pulled from the freezer the specimen has noticeably changed. It has a slight white, almost white frost or texture to it. Please see attachment and table below.
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
al the stalk and root if you want to avoid getting lots of red dye in
Hypothesis: To investigate the effect of different concentrations of ethanol on the permeability of beetroot cell membranes.
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.
4.Measure 35mL of warm water and add them into each of the 4 test tubes at about roughly the same time. It is essential that the water is warm. Do not seal the test tube.
At low temperatures (5oC-15oC) the rate of photosynthesis will be slow, as the enzymes of the plant do not have enough energy to meet substrate molecules. However, as the temperature increases, there will be a greater rate of photosynthesis, especially as the enzymes approach the optimal temperature. Although once the increase in temperature has gone past the optimal temperature, enzymes will begin to denature and the rate will decrease until there is little or no oxygen being produced by
Next, fifteen drops of potato juice were added to each test tube. Simultaneously, ten drops of Hydrogen Peroxide (H2O2) were added in all test tubes at the same time. All test tubes were gently shaken to mix the solutions and put to rest. After three minutes, the height of the bubbles of the three test tubes were measured at the same time. Then, the test tubes were exposed to different temperatures.
Cut the potatoes using a cork borer approximately 5cm in length and 1cm in diameter. Using the appropriate tool cut the potatoes into cylinder form measuring the cylinders with a ruler.
For this reason the water used will be at room temperature (23° approx) and will be performed on the same day to allow no margin for any discrepancies.
until 50 C because at 55 C it was only just measurable and this may be
The aim of the sixteenth of November experiments was to observe how three different solutions with various sucrose concentration influenced osmosis in relation to three onion cells and the impact on the cells structure.
Collect to 2 large beakers both large beakers are to be filled with hot water (labtutor). Then obtain seven conical tubes these will be used to collect the levels of gas, you will also need test tube a stopper and a plastic tube (labtutor). You want to fill the conical tube to at least 50 ml of water (Cressy). Take the four conical tubes filled with water and place two in each beaker, to do this you must invert the tube and cover the release hole as to not lose any water (Cressy). Then place the beakers with the tubes in the bath so they can be at the same temperature as the bath (Cressy). Next mark all of your test tubes in number order to be sure which tube contains what concentrations and pH (Cressy). Having mixed a solution to the specifications of 2.5 ml of glucose in all tubes, 3 ml of yeast in 2 tubes of pH 5, 2 tubes of pH 9, and the single pH 7 tube, the remaining two tubes will contain no yeast as they will be negative controls. Next add 2 ml of pH buffer 3 tubes will receive pH of 5, three will receive a pH of 9 and a single tube of pH 7. Finally add pure water to make sure all test tubes have 10 ml of solution. When making the solutions