Experiment Comparing the Osmotic Behaviour of Two Different Examples of Plant Tissue
Aims Perform a safe reliable experiment to find the effect of varying the molarity of solutions on the mass of potato and radish cells. We will conduct an experiment comparing the osmotic behaviour of the following plant tissues: 1. ... Earlier in the year we performed a similar experiment to show how osmosis works we found, that the higher the molarity of the solution the tissue is placed in the higher the reduction in mass is this also works in the opposite direction, the lower the molarity the mass increases to a greater extent. ... 5M in a low molarity solution it has a lower water potential than the surrounding solution so water enters by OSMOSIS , so continuing with this process if placed in a higher molarity solution the potato loses water to the solution surrounding the tissue again this is by the process of OSMOSIS. ... Water is lost from various parts of the cell at varying times for example in a regular and simple plant cell it would be removed from the cytoplasm firstly then through the vacuole by passing through the tonoplast, once this has happened the membranes next to the cell wall retract and shrink changing the shape of the living cell this is known by the term Plasmolysis. ... If you put a plant cell in distilled water as the plant cell has more sugar solution than the water outside of the cell it draws it in through osmosis, it then proceeds to swell up through the increased volume of solution it contains. ... Both plasmolysis and turgidity are visible from just looking at a plant as the former produces a wilted posture that may be the cause of death for a plant deprived of water and the latter produces the much stronger upright posture resembled with a healthy plant due to watering. ... 4M will cause it too become turgid and to have gained mass if needed one could tell this by just holding or feeling the tissue as it would have a strong sturdy feel to it would also be slightly heavier. ... However, the other tissue we are using is already much firmer than that of a potato and as we haven’t done this experiment before I can only guess what difference this will make but I guess it would have a higher water potential than that of the potato but this will be shown in the graphs of the results. This may mean that the Chinese radish is less affected by the molarities we have chosen solely on the results of our earlier experiment into osmosis. ... Earlier as I have already said we did a copy of this experiment perhaps simpler in that we only used a single tissue type it was a potato tissue. ... The different molarities needed, will be created by hand as accurately as is possible by mixing 1. ... As we had to choose eight different make ups it would have been impossible to provide a minutely accurate graph but these numbers are acceptable for the range I estimate this test to use. ... When we put plant tissue into distilled the reason it expands is mainly because of the fact that the cytoplasm already contains sugars and salts. ... The Effect Of Osmosis on Plant Cells Plant cells generally have a water potential which is markedly lower than that of their immediate surroundings. ... However, when induced by experiment it can help us to understand the water relations of plant cells, as we shall see in a moment. The effect of osmosis in plant cells is summarised below: Turgor Provided there is plenty of water in the environment, a plant’s cells are usually surrounded by a watery solution whose solute concentration is lower than that inside the cells - indeed, the cells walls will be saturated with such a solution. ... If turgor is lost or reduced, the plant droops. ... It is impractical to weigh them separately, as it is impossible to remember which chip weighed X at the beginning and then compare it to the same chips weight at the end of the experiment and three chips ought to reduce the likelihood of three anomalous results. ... Find the percentage increase/decrease using the equation: Difference Between Original and Final Mass X 100 Original Mass There are something’s that are necessary for a fair experiment I will go over most of them in the conclusions but I would like to say a few things now firstly the water in this experiment must be pure without any minerals in it secondly it is paramount that the same environmental conditions are enforced over the whole test if the room has windows the test tube racks must be kept out of sunlight or in partial shade. The measurements throughout the whole experiment must be conformed upon rigidly. ... ) It is obvious the need for this part of the apparatus list as there would be no experiment without them. · 16 Test tubes these are the containers for the solutions we put the vegetables in we need eight to make the experiment work as there are eight different solutions used for testing the chips. ... · 250ml Glucose solution this was needed to create the solutions required by the experiment 250ml was deemed enough to supply the tubes in preparation · 250ml Distilled water solution this was needed to create the solutions required by the experiment 250ml was deemed enough to supply the tubes in preparation · Pippette/2 10ml syringes these were need to measure out reliably how much solution we needed to put in the test tube · 2 test tube racks we needed these to hold the tubes during the experiment.