Experiment to Investigate Osmosis in Potatoes Essay

The go of this audition is to enquire the reason of weewee in and out of arrange prison carrels. The kiosks elect for study pull up s throngs be interpreted from tater furnishrs. Firstly I ordain explain what osmosis is. Osmosis is the race of irrigate from a region of blue irrigate assimilation with a semi pervious membrane to a region of menial body of piddle tightfistedness. This definition contains cardinal master(prenominal) statementsa) It is the passage of piss by means of and through with(predicate) a semi permeable membraneb) It is the passage of peeing from a region of naughty peeing dousingc) It is the passage of pissing to a region of low piddle immersion. solely the to a higher place statements atomic number 18 include in the definition, and define real aspects of it.Semi-permeable membranes ar precise thin layers of real which eachow some things to pass through, much everywhere counteract others. A mobile ph single mem brane is semi permeable. They exclusivelyow sm whole molecules comparable oxygen, water, amino acids etc. to pass through al genius go forth not allow lifesizer molecules like sucrose, starch, protein etc. through. A region of blue concentration of water is ein truth a very load settlement of something like sucrose or pure water. In each theme in that location is a lot of water a risque concentration of water. A region of low water concentration is the opposite of the above, i.e. a very high concentration of sucrose conduce a low water concentration.The water substance of plants varies depending on environmental conditions. In prop plants this water plays a vital role in the corroborate of tissues and the transport of materials approximately the organism. Lack of water leads to wilting and finally death. Water is mainly absorbed through the roots, which argon covered in curiously adapted root hair kiosks, with larger-than-life surface beas and thin carrelu lar teleph wiz groynes to countenance absorption. It is displace up the plant through xylem vessels by a pull resulting from the vaporization of water through thestomata on the leaves.This evaporation is called transpiration and the xylem flow resulting is called the transpiration stream. Soluble food substances form during photosynthesis are transported around the plant in the bast fiber tubes. This movement of water through the plant in the xylem vessels or phloem tubes is similar to the flow of blood in humans as it transports soluble mineral salts, nutrients and auxins, (plant hormones), from place to place. The evaporation of water from the leaves as well(p) as removes heat energy from the plant and helpers to prevent overheating.Transpiration pulls water up the plant stanch still osmosis is the process whereby water is bony into or out of cubicles and tissues. Osmosis is the flow of water by diffusion through a differentially permeable membrane from areas of high water concentration to regions of low water concentration. The diagram below illustrates thisWater tush freely pe shekelsrate all membrane. The cellu resort cell wall does not act as a semi permeable membrane and pull up s coins allow most substances that are dissolved in water to freely pass through it.Whether water levys the cell by osmosis or not entrust depend on the chemical equilibrium in the midst of outer and internal solute concentrations and the state of the cell. If the answers on each side of the differentially permeable membrane are equally laborious consequently on that point allow be no give notice movement of water across the membrane. This is called an equilibrium state and the settlements are referred to as being isotonic. A resolvent that contains more(prenominal) solute particles than another, and is hence more concentrated, is referred to as being hypertonic. The less concentrated solving is hypotonic. This concentration of solute particles is usually described as a thou.Even if the solute concentration external to the cell is hypotonic to the vacuole contents the cell try outament not continue to take in water by osmosis for ever. The cellulose cell wall provides a rigid roadblock to uncontrolled expansion. A cell that is skilful of water is called gusty and quarternot expand however as the outward extort on the cell wall is balanced by the inward military strength of the stretched wall. This wall push is called turgor insistencyand the internal outward force on the wall is called osmotic pressure.At the other extreme, a cell hardened in a solution that is hypertonic to its contents volition lose water by osmosis. The cytoplasm will free to exert a pressure on the cellulose cell wall and the cell, described as flaccid, will lack support.Water hurt can continue to such an issue that the cytoplasm, and attached cell membrane, contracts and detaches from the cell wall. A cell in this condition is verbalize to amaze undergone plasmolysis. This very rarely, if ever happens in nature.As osmosis is the diffusion of water molecules and as diffusion is the random movement of particles from areas of high concentration to low concentration it cleverness be expected that any actor outs that animate up or slow heap the movement of these particles would affect the rate of osmosis. using knowledge of the process of osmosis and with a ripe(p) under bideing of hoagyity I should be able to determine the solute concentration of the vacuoles in stump spud tuber cells. As it would be impossible to prise with any course of accuracy the expansion or compressing of cells on an individual basis I hurt decided to envision at collect or termination of water in terms of maturation or decrease in good deal. Mass, I feel, will be a more faithful way of recording the transform of the white stump spudes as when measuring space, it does not take into trace the throw in diameter of the h alt. I will also look at the increase or decrease in continuance to verify the accuracy of my results and equality the two readings. A cell determined in an isotonic solution should cross-file no trade whereas one hardened in a hypertonic solution will lose circle.For this experiment, I will eat to choose a factor to veer. These factors are Molarity of the sucrose solution Surface area of the stump spud chartic symbol of white stump spud vine calld Age of the potato pH of the sucrose solution TemperatureThe factor I ingest chosen to vary is the torpedoity of dinero solution as I believe this will be easy to regulate as the concentration can be easily modify using distilled water. I will use 1 molar solution and shorten the concentrations as destinen belowMolarity of cole solutionAmount of waterAmount of sucrose solution0.0500.2410.4320.6230.8141.005For this experiment I will have 1 large potato to produce 18 potato tubers phellem borer distilled water 1 molar borecole solution pipettes 18 try tubes ruler to measure aloofness of potato tubers electric balance to measure the push-down storeI have selected the above equipment because I feel it will help me to ensure consummate results. To ensure a fair test I will take all my potato samples from the like potato using the kindred cork borer and keep all of my setup the same. I will try and transact each potato tube the same. I will measure each potato tube separately to ensure stainless measurements and carry out the procedure 3 times for each metre tested. This will mean that I will need to measure 18 potato tubers. trey results will enable me to take an bonny out result, making the results, hopefully, more precise and reliable. If one of the results jutms very different to the others, I shall chance on it as an irrational result and recapture the reading.When I carry out this experiment, I will get a potato and take some tubes from it using a cork borer I will then(pre nominal) cut these tubes into shorter spaces and measure the length and caboodlees of each of the 18 lengths. All the lengths will be cut to 25mm. The solutions will be altered according to the molarity required and cm3 of each solution pose in each test tube. individually molarity will occupy three test tubes. The fails will then be throw up into each test tube and left over night. They will then be taken out of their test tubes, dried lightly with a base towel and the new mass and lengths recorded. once the results have been collected, they will be tabulated and analysed. A chart will be pull and any trends noticed explained.Prior to the experiment we carried out a short fly test, using potato splinters and solutions of strength 0.0, 1.0 and 2.0 molar solutions. The chips were25mm in length each, and each chip was put in 5 cm3 of either distilled water/1.0 molar / 2.0 molar sugar solutions and left for 30 minutes. The potato chips were then deliberate and the resu lts recorded. They are shown belowChipSolution1Water21.0 molar32.0 molarChip numberOriginal lengthResultant length125mm29mm225mm24mm325mm20mmThese results show that a potato chip placed in water will crystallise in length, a weak sugar solution will lose length and a strong sugar solution will lose length also. The results from this test will allow me to choose an take away range of moralities in order to let on out what the concentration is within the cell vacuole. I am going to check up on 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 molar sugar solutions. I have chosen these concentrations to try and accurately ferret out when there is no net movement of water, hence the concentration of the cell vacuole.From introductory work done on osmosis, I predict that molarity and amount change in mass/ length will be indirectly relative. I gestate there will be a oppose correlation mingled with the two. I think that there will be both exit and gain in mass discovered. I think the graphica l record will look like this and there will be no plasmolysed on my graph, as I do no expect my measurementsto go that far. I hope to be able to commit the battery-acid when there is no net movement of water.Analysis of ResultsThe Consequences of Osmosis in plant cellsPlant cells always have a strong cell wall contact them. When the take up water by osmosis they start to swell, but the cell wall prevents them from bursting. Plant cells become turgid when they are put in dilute solutions. magnanimous means swollen and hard. The pressure inside the cell rises, eventually the internal pressure of the cell is so high that no more water can enter the cell. This liquid or hydrostatic pressure works against osmosis. Turgidity is very consequential to plants because this is what makes the green parts of the plant stand up into the sunlight.When plant cells are placed in concentrated sugar solutions they lose water by osmosis and they become flaccid this is the exact opposite of turgid . If you put plant cells into concentrated sugar solutions and look at them under a microscope you would see that the contents of the cells have shrunk and pulled away from the cell wall they are said to be plasmolysed.When plant cells are placed in a solution which has exactly the same osmotic strength as the cells they are in a state mingled with turgidity and flaccidity. We call this incipient plasmolysis. early means about to be. When I forget to water the potted plants in my study you will see their leaves droop. Although their cells are not plasmolysed, they are not turgid and so they do not confirm the leaves up into the sunlight.Graph 1 shows the intermediate destiny change in length of the potato tubers. It shows that as molarity increases the average change in length decreases. The graph drawn looks accurate as the toot did not have to be one of stovepipe consort, but went through all of the points plot present that all the readings were accurate. The potato tuber s gained/ loss length, the molarity increases the sugar solution becomes more concentrated, and moreconcentrated than inside the cell. At 0.2M solution there is no net movement of water. As the strength of the concentration increases the cells shrink and become flaccid.Graph 2 shows the average character change in mass of the potato tubers. It shows that as molarity increases the average change in length decreases. This graph is very similar to the graph video display the length loss or gain, but appears less accurate as there is an anomalous result. This is at 0.4 molar, it lies off the best-fit curve drawn by 9.2%. The curve is one of best fit and follows the same trends as graph 1.My results seem fairly accurate and although the graph showing length seems to be more accurate as it is a curve that goes through all of the points, it lone(prenominal) shows the change in length, and not in mass. The graph showing mass change 2 gives a more accurate tantrum of what happened as it takes into account the expansion of the potato both ways and has a broader percentage change range. This means that instead of save spanning 30% in total (as does graph 1) it spans 80% (as does graph 2). This gives a broader sphere of results and is therefore more accurate, as the mass is a more accurate result than length as the potato chip will get wider as well as longer. My results do seem to be reliable, as the graphs drawn support my sooth stateing and seem accurate as they all lie on a serene curve.ConclusionFrom the results obtained, I can finish that the average gain or loss in mass of the potato chip is indirectly proportional to molarity. I can also say that average gain or loss in length of the potato chip is indirectly proportional to molarity. Both of the results show a negative correlation. I can now say that the more concentrated the solution, the more mass/length is lost. This is because the water inside the cell moves out, causing the cell to shrink. When the c ells are in a less concentrated solution they gain in length and mass as water is taken into the cell and the cell swells. The results gave enough information to support my original prediction. Both of the graphs cut the x-axis at 0.2, showing that the molarity of the internalsolute of a cell is 0.2m. This also shows that my results were very similar and reliable.EvaluationMy results seem to be very accurate. I can tell this because when the points were plot they all lay on the curve, apart(predicate) from one anomalous result, 0.4Mon the graph showing mass. There was however only one anomalous result and the others were all very reliable. This whitethorn have been because the results had an average taken so it may not have been accurate. I could increase the accuracy by taking more repetitions which should make the average more accurate. As the potatoes were left over night, the temperature changed which may have affected the results, but it should not have made a drastic differ ence to the graphs as all of the potatoes were subjected to exactly the same temperature changes.This could be meliorate by placing the test tubes into a water bath so they were kept at a constant temperature. The same potato was used in each of the experiments, which may also have contributed to the reliability of my results. The mass was more accurate to measure for many an(prenominal) different reasons. Length does not take into account the change in diameter of the chips, and you can not measure fractions of millimetres on a ruler, but the electric balance will record change from 2 decimal places,e.g. mass 1?43 1?34length 25 23whilst length can only be measured to the nearest millimetre. For the mass, we had to be careful that all the potato chips were dried in the same way as this may have altered the reading. This may have been what caused the anomalous results, as it was lighter that the best fit line i.e. some water may have been lost through harder drying, or squeezing during the drying process. If some of the water evaporated overnight, it would have incresed the molarity of the solutions, thus making the results innaccurate. This could be combatted by putting a stilt in the top of the test tubes to stop the evaporation and keeping the sugar slution concentrations the same.To remediate the accuracy of the results I would include more concentrations to perplex the point of plasmolysis as in my experiment, I did not get to the point of plasmolysis in my experiment, so if I was to go through this experiment, I would investigte a wider rage of concentrations to investigate furthur and increase accuracy. I would also increase the repetitions to 5 per molarity and increase the molarity to try and find the point of plasmolysis. I could also decrease the range between each molarity (every 0.05 for example) to try and find the exact concentration of the potato cells where there is not net gain. This investigation was succesful but could still be made m ore accurate by some of the above ways.