Cell Membranes and Transport Essay examples

At five minute intervals over the next fifteen minute period, record the color intensity of the solution of each test tube.

And finally into test tube 3, I pipetted 1.0 ml turnip extract and 4.0 ml of water. The contents of test tube 1 was poured into a spectrometer tube and labeled it “B” for blank. “B” tube was now inserted it into the spectrometer. An adjustment to the control knob was made to zero the absorbance reading on the spectrometer since one cannot continue the experiment if the spectrometer is not zeroed. A combination of two people and a stop watch was now needed to not only record the time of the reaction, but to mix the reagents in a precise and accurate manner. As my partner recorded the time, I quickly poured tube 3 into tube 2. I then poured tube 2 into the experiment spectrometer tube labeled “E” and inserted it into the spectrometer. A partner then recorded the absorbance reading for every 20 seconds for a total of 120 seconds. After the experiment, a brown color in the tube should be observed to indicate the reaction was carried out. Using sterile techniques, any excess liquid left was disposed

3. Explain your prediction for the effect Na+ Cl- might have on glucose transport. In other words, explain why you picked the choice that you did. How well did the results compare with your prediction?

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 same solution of 0.5 ml BSA was then added from test tube 1 to the test tube 2 after being properly mixed, and from test tube 2 the solution was being added to test tube 3, and so forth all the way up to test tube 5, with the same exact procedure. From the last tube, we then disposed the 0.5 ml solution. After above procedures, we now labeled another test tube “blank”; 0.5 ml blank distilled water was purred into the tube with the serial dilution of 1:10. We also had a tube C labeled “unknown” with the same 0.5 ml of solution. And after adding 5ml of Coomassie Blue to each tube (1-5) and to the blank, the result of absorbance was read at 595 nm.

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.

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.

5. The degree of precision was to 3 significant figures obtained with the spectrophotometer. The major source of error in our experiment was not calibrating the spectrophotometer with distilled water.

Abstract: The purpose of this lab is to separate and identify pigments and other molecules within plant cells by a process called chromatography. We will also be measuring the rate of photosynthesis in isolated chloroplasts. Beta carotene, the most abundant carotene in plants, is carried along near the solvent front because it is very soluble in the solvent being used and because it forms no hydrogen bonds with cellulose. Xanthophyll is found further from the solvent font because it is less soluble in the solvent and has been slowed down by hydrogen bonding to the cellulose. Chlorophylls contain oxygen and nitrogen and are bound more tightly to the paper than the other pigments.

For our lab, we have six beakers of water. Three of the beakers contain high temperature water that range from 46 ℃ to 55 ℃, while the other three beakers contain room temperature water that range from 22 ℃ to 23 ℃. Then, we take six different colored Alka Seltzer tablets, and place them into the beakers one at a time. We record the length of time it takes for each Alka Seltzer to dissolve

Figure 2: Dye percents versus absorbance in a control, 10%, 20%, and 30% azide solutions.

When the beetroot sample is heated for a longer period of time, it is exposed to the vigorous and frequent vibrating molecules for a longer duration. This further disrupts the cell membranes making them more fragile, thus more pigment will leak out into the external solution. With more leakage of the betacyanin pigment, the % transmittance should be lower, indicating that the % of light that is able to pass through the beetroot solution should be less as duration heated increases.

Apparatus: Spectrophotometer (UV-1201), cuvettes, water bath (set at 37°C), 200µl and 1000µl micropipettes and test tube

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.