Lastly carbohydrate molecules of the membrane are relatively short-chain polysaccharides, which has multiple functions, for example, ell-cell recognition and acting as receptor sites for chemical signals. The plasma membrane is a permeable membrane. An important role of the plasma membrane is to maintain the integrity of the cell, holding the cell contents together. Membrane permeability is a quality of the cell’s plasma membrane which allows certain substances to pass while forming a barrier against others, controlling exchanges between the cell inner and outer environment.
Substances passed inside include for instance, water, respiratory gases like oxygen and carbon dioxide, nutrients such as glucose and essential ions. On the other hand, waste products can be expelled and components required to assemble cell walls can be secreted out through the membrane. Because of the permeability of the plasma membrane, cells can extract the amino acids, fatty acids, sugars and vitamins need to carry out its daily functions. The movement across the plasma membrane of living cells is continuous and sustains the cells.
Beetroot is a vegetable that contains a rich source of potent antioxidants and nutrients which is important for cardiovascular health. Beautician, a red pigment, can be obtained in the vacuole of beet root cells, and is commonly seed industrially as red food coloratura or ink. In exploring the permeability of a beetroot membrane which contains a colored pigment, additional research was conducted regarding light and the optical spectrum. The visible spectrum of light is the portion of the electromagnetic spectrum which is visible to the human eye.
The human eye would respond to wavelengths from approximately Mann to Mann. A colorimeter can be used to measure the absorbent of specific solutions at a particular wavelength of light. Colorimeter is an instrument that compares the amount of light getting through a solution with the amount that an get through a sample of pure solvent. A colorimeter contains a photocell which is able to detect the amount of light which passes through the solution. Results from the colorimeter can be read as absorbent and % transmittance outputs. (Source: http://www. Weeklies. Com/what-is-a-colorimeter. Tm) Despite all attempts of movement of substances in and out of the membrane to sustain the cell, conditions can be manipulated leading to the malfunctioning of the cell, disrupting its phosphoric bilateral. Examples of conditions include heat, coolness, and use of detergents and solvents. In conclusion, this investigation will have a focus in the condition of heat. It will explore the effects that the duration of heating a beetroot has on the permeability of its cell membrane. Research Question: How do the different durations that the beetroot is heated for affect the permeability of the beetroot membrane?
Aim: The aim of this experiment is to determine whether the different durations of heating a beetroot would affect its membrane permeability. This would be done by changing the amount of time of which the beetroot sample is heated, and measuring its % transmittance of light. Using the data collected, loud determine the permeability of the beetroot membrane under heating conditions. Hypothesis: I predict if the beetroot sample is heated for a longer period of time, the permeability of the beetroot membrane should increase. This is because when the beetroot sample is heated, kinetic energy is added upon it causing molecules to vibrate faster.
The vibrations break up hydrogen bonds in the membranes which link the amino-acids. Thus it forms holes, disrupting the membrane of the beetroot core which essentially prevents the beautician pigment from leaving the cell. Also, when exposed under heat, the cholesterol, alcoholics and phosphoric 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, beautician pigment in the innermost compartment will leak out. 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 beautician 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. Source: http://www. Weeklies. Com/what-is-membrane-permeability. HTML) Based on previous knowledge, research and the above prediction, I would expect to get results similar to: The data collected of % transmittance can then be used as an indication of hanged in membrane permeability of the beetroot. Variables: Independent – duration of time in seconds that the beetroot core solution is heated under ICC: 120,1 50 Dependent – transmittance in percentage (%) of beautician pigment present in beetroot core solution Controlled – 1 . Diameter of beetroot core (mm) 2. Engel of beetroot core (22 mm) 3. Temperature of which beetroot is heated in (ICC) 4. Volume of denizen water per trial (ml) 5. Colorimeter filter (green Mann transmittance) 6. Beetroot 7. Cavetti *My experiment was controlled by using denizen water, in order to get 100% remittance when calibrated. Control of Variables: The diameter of the beetroot core can be kept same using the same sized core borer of mm each time. The length of the beetroot core can be kept constant by measuring the lengths with fernier calipers (В±O. CACM) and using a knife, cutting them to same lengths of mm.
The temperature of which the solution is heated in can be controlled by using the same ICC water bath for all the trials, and using the thermometer (В±O. ICC) to ensure that the water bath is constantly at ICC. The volume of denizen water should all be at ml, this can be controlled by sing a measuring cylinder (В±O. Ml) and a dropper to accurately measure out the correct amount. The filter of the colorimeter should be controlled to green Mann transmittance throughout all the trials, this can be done by double checking that the correct filter is being used at the start of every trial.
Materials Used: Stopwatch (В± 0. 01 sec) Measuring cylinder (В±0. Ml) Colorimeter (В± 0. 01 Thermometer (В±O. ICC) Fernier calipers (В±0. CACM) 1 Beet root 1 Core Borer 1 Water bath: ICC 2 Test tube racks 6 Suspects 20 Test tubes Test tube rack Beaker Computer Dropper Knife Safety mat Tweezers White tile Denizen water Extension: Silver nitrate was also used in a pilot experiment was conducted using carrots. From it we learnt that we should take the cores from the outside layer because as a beetroot grows, new cells are formed on the outside layer, therefore less dead membranes.
I thereby conducted the experiment using this knowledge gained. A risk assessment has been conducted in the process of planning this investigation and the possible risks may be glass breakage or burnt by hot water. These dangers can be prevented with more careful actions around the lab. It s also essential that safety glasses are worn during the entire course of the experiment. Method: 1 . Take all safety precautions: wear safety glasses, hair tied back, wear close- toed shoes, ensure a clear surrounding with no obstacles in order to perform the experiment. 2.
Gather all equipment (see equipment list) 3. Cut out 5 beetroot tubes, mm in diameter, on white tile. Control variable 1 by using the same No. 3 core borer for cutting all beetroot tubes 4. Measure and cut length of the beetroot tubes to mm (В±0. CACM). Control variable 2 by measuring length using fernier calipers and use a knife to cut beetroot tubes o correct length 5. Bath beetroot tubes in a beaker of denizen water to get rid of the dead membranes after cutting 6. Measure ml of denizen water with measuring cylinder (В±O. Ml) into 5 test tubes.
Control variable 4 by using a dropper to precisely measure ml of denizen water into each test tube 7. Using tweezers put a beetroot core into each of the 5 test tubes with denizen water 8. Place the 5 test tubes on a test tube rack and put them into an ICC water bath. Control variable 3 by measuring with a thermometer (В±O. ICC) to ensure correct temperature 9. Take out first test tube after 30 seconds, second after 60 seconds, third after 90 seconds, fourth after 120 seconds and last one after 150 seconds. Use a stopwatch (В± 0. 01 sec) for accurate timing 10.
Pour solutions from the 5 test tubes into 5 suspects and screw on cap, gently rock the Cavetti back and forth to evenly mix the solution without creating bubbles 11. Pour denizen water into a Cavetti and screw on cap to create a ‘blank sample’ 12. Label suspects: Cosec, assess, assess, assess, access, and access 13. Set up data logging programmer and plug in colorimeter (В± 0. 01%) 14. Select wavelength for measurement: green (Mann) transmittance 15. Calibrate colorimeter with ‘blank sample’ created previously (step 1 1) to ensure the initial reading is indeed 100% transmittance 16.
Insert Cavetti labeled assess containing the beetroot solution into the chamber of the colorimeter and shut lid 17. Take reading for 5 seconds and record 18. Take readings for the remaining 4 suspects of beetroot solution (labeled assess, assess, access, and access) and record data Repeat experiment for 3 trials. Data Collection and Processing: Data Table 1: I Raw Data: % Transmittance of Beautician Pigment in Beetroot Sample Solution I I Duration heated (sec) I Green (Mann) transmittance Reading I I (Stopwatch В±O. Execs) В± 0. 01 %) I Trial 2 190. 1 177. 3 160. 1 | 50. 3 148. 4 Data table 2: I Trial 3 | 90. 3 169. 0 | 65. 9 | 54. 3 | 38. 5 I Trial 4 195. 1 179. 3 | 58. 7 152. 9 140. 0 1 1120 1 1150 I(Colorimeter I Trial 1 187. 5 76. 7 62. 4 | 52. 8 149. 4 Average % Transmittance of Beautician Pigment in Beetroot Sample Solutions (4 trials) I Duration heated (sec) (96) В± 0. 01 90. 8 75. 6 | 61. 8 | 52. 6 44. 1 Graph 1: Graph 2: 1 130. 0 I (Colorimeter 1 160 Interpretation of Results: The above results gained support my hypothesis.
The graph of the average exults is a decreasing exponential curve. It shows that the longer the beetroot core solution was heated, the lower the % transmittance of its beautician pigment, and hence the beetroot is more permeable. This is due to the fact that the longer the beetroot tube was heated under ICC, the longer it was exposed to the vigorously vibrating molecules cause by heat energy. Thus the membranes were further disrupted through the breaking of hydrogen bonds linking the amino-acids, forming holes in the membrane.
Secondly as exposed under heat for longer durations, the lipid part of the membrane became liquid ND more fragile, increasing the permeability in the surface of the membrane. More beautician pigment leaked out into the external solution, resulting an observation during the experiment, that the color of the solutions darkened as the beetroot is heated for longer. Due to the fact that the beautician pigment prevented some light from passing through the solution, the darker the beetroot solution, lower the % of transmittance.
The exponentially decreasing curve can be explained by the fact that there is a limited amount of Beautician pigment in cells. Therefore as the beetroot tube is mutinously heated for a period of time, less and less pigment would leak out each time. The data displayed on graph 1 presents 2 minor anomalies, on trial 3 and trial 4. In trial three, the data point accounting for %transmittance at assess of heating is lower than the trend curve. This was caused by a human fault, as when transferring the beetroot sample solution to the water bath before heating, a portion of the sample was spilt.
This may have affected the concentration of the solution, as the pigment leaked out was then concentrated in less volume of denizen water. Another anomaly is regarding trial 4, the data point accounting for % remittance at assess of heating. It is lower than other data points on the trend curve. This was yet another human error, possibly caused by the mix up test tubes between classmates while in the water bath, as I haven’t taken the liberty to label my test tubes beforehand. Graph 2 shows the average transmittance of Beautician from all 4 trials.
The data point for 60 seconds heated displays a rather large discrepancy between the highest and lowest %transmittance obtained from the 4 trials. This is shown by the error bar that the lowest value differs largely from the average value. However despite the anomalies, an obvious exponentially decreasing trend can be observed through conducting 4 trials. In conclusion the data collected supports my hypothesis, as it shows a lower %transmittance of the beautician pigment in beetroot solution, as the sample solutions are heated for a longer period of time.
Thus from the data of %transmittance readings, it can be concluded that the longer the beetroot sample is heated, the more permeable it is. Evaluating Procedures: The method of this experiment was well written. However there were external factors that failed to control while performing the experiment. . The way I shook the Cavetti – at times I shook too vigorously, and other times I shook it too feebly. This affected the data I collected as some samples which were not shaken hard enough ended up having some pigment settling at the bottom, which may have led to a less accurate reading of light transmission. . No identical beetroot cores – one particular section of beetroot will only contain a certain amount of pigment, no two pieces of beetroot are identical. Therefore having used different sections of beetroot for each testing, possible differences in permeability and amount of pigment may have occurred. 3. Steam within water bath – due to high temperatures in the water bath, steam may form towards the lid of water bath, causing water droplets to drip down into the test tubes, affecting the actual volume of water present inside the test tube.
Several improvements can be made if were to do this experiment again: 1. Control method of shaking Cavetti – next time I can control the way I shake by either controlling the number of shakes per Cavetti, or controlling the duration in seconds of which I shake the Cavetti. Additionally, before the actual experiment, I would do a pilot run to determine approximately how many shakes loud be required so that that none of the pigment would end up settling at the bottom. This is so that can obtain a more accurate reading of light transmission. . Use multiple beetroots – a possible method to improve the fact that no two pieces of beetroot contain the exact amount of pigment, may be using multiple beetroots and taking the same section of each beetroot. In order to act accordingly, before the actual final experiment, I must attempt to prove that indeed, taking same sections from different beetroots can improve the discrepancies amount of pigment contained. I can possibly do a pilot experiment o test whether this assumption is correct.
However, I predict that even though this method may lessen the difference in amount of pigment contained, it will not completely eradicate this problem, as beetroots are of different sizes and shapes, which may also affect the amount of pigment it contains in one specific section. Overall, my set of data collected is relatively reliable, as the experiment was conducted altogether 4 times in order to get more results for comparison and higher degree of accuracy. However some human errors occurred during the experiment, such as accidentally spilling the sample solution and carelessly axing up test tubes.
All these human faults can be solved next time by being more careful while handling samples, and also taking the liberty to label the test tubes beforehand. Lastly in the future, I can conduct further investigations on how different temperatures may affect the permeability of the beetroot membrane, for example, the temperature of which the beetroot core solution is heated under. I can do this by using different temperature water baths to change the temperature, and then measure the %transmittance of the pigment leaked out from those beetroot core solutions with different temperatures.