Osmosis lab diffusion called osmosis, which involves in selective transport of water molecules across a selectively permeable membrane (lab manual 2nd edition) it was hypothesized that osmosis will occur when there is an uneven distribution of solute in a solvent. Aside from obviously being a photocopy and a couple of minor formatting problems, this is a laudable lab activity for exploring osmosis biology groups cut potato chunks into equal volumes and record the mass of each. Basics of the elodea lab for learning about movement of water in/out of cells. The passive movement of different substances like water, ions, waste, and nutrients, between cells in an organism, and between organisms and their environment high concentration to low concentration.
Osmosis is the diffusion of water across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration the process occurs without any expenditure of cellular energy and continues until equilibrium has been reached (ie, when solute concentrations are equal on both sides of the membrane. Observing osmosis, plasmolysis and turgor in plant cells class practical or demonstration a single layer of plant cells is placed on a microscope slide and either distilled water or 5% sodium chloride solution is added to the cells. C osmosis - plasmolysis of an elodea leaf 1 prepare a wet mount of an elodea leaf and observe it under the microscope at 430x 2p deld l fb dd d f di hl id ( l) l i. When regular water was added to the elodea densa leaf you could see more chloroplast then when there was salt water added this is because the salt water solution is hypertonic the effect of placing an elodea cell in a hypertonic solution is the cell to shrink all the organelles and parts in the cell then become closer together because of the.
Osmosis and diffusion lab essay sample the purpose of this lab was to observe the rate of osmosis and diffusion, as well as the effect of molecular size of the particles on this rate part i of the lab was a demonstration of osmosis and diffusion, that dealt with raisins in different liquid environments, each with a different concentration of. Diffusion, osmosis, and tonicity simple diffusion particles in solution are generally free to move randomly throughout the volume of the solution. Obtain a leaf from an elodea or water sprite plant and examine the material first at low power (100x) and then at high power (400x) (c) in an even more concentrated solution a 2 cm cube each group will cut 3 agar cubes (a 3 cm cube.
We saw that all solutions caused plasmolysis in the elodea leaves except for the control the major difference between all the trials was the amount of time it took for plasmolysis to take place depending on the concentration of the solution. Osmosis is the process whereby water moves across a cell membrane by diffusion diffusion takes place when the molecules of a substance tend to move from areas of higher concentration to areas of lower concentration. Osmosis is affected not only by the solute concentration but also by the resistance to water movement in the cell by the cell wall this resistance is called turgor pressure. The experiment was done by growing elodea in an aquarium with one, five and ten goldfish and also in a tank without any goldfish hypothesis the elodea plant will grow faster in the aquarium with goldfish.
Elodea is a common aquatic plant related to hydrilla it has leaves of only two layers of thickness it has leaves of only two layers of thickness in this exercise, the thin leaves of elodea will be useful in exploring some of the principles of osmosis. Osmosis is the diffusion of water across a membrane from an area of high water concentration to an area of low water concentration this movement of water may be harmful to cells a hypertonic solution can result in the plasmolysis of a cell when the water in a living cell osmoses out of the cell and the cell becomes dehydrated. Elodea is a freshwater plant commonly used for aquariums and it can be purchased at most pet stores the leaves of elodea are only two cells thick and are ideal for the microscopic study of the. In our experiment we put baking soda in in our elodea plant so as the days went by the elodea plant started losing color and the bubbles started to disappear our hypothesis we said that if we put baking soda in our elodea plants it would have less oxygen and we were right. Lab 3 osmosis and diffusion 4 1 obtain a leaf from an elodea plantplace it in a drop of water on a slide, cover it with a coverslip using the scanning power objective, find the sample and bring it into focus.
Shelled egg's external membrane and an elodea leaf to demonstrate how osmosis can occur in solutions where make sure to address the problem and your hypothesis. Exploratory activity: osmosis in elodea cells or onion cells introduction: one of the functions of the cell membrane is to control the flow of materials into and out of the cell in this investigation, you will observe the effects of placing plant cells in solutions of various concentrations. Hypothesis: if a solution is hypertonic to the elodea leaf, then the cells will shrivel and become flaccid however, if the solution is hypotonic to the elodea leaf, then the will gain fluid and become turgid. Osmosis in elodea leaf cells purpose background basic concepts of preparing solutions: methods & materials what effect does saline concentration have on the integrity of elodea plant cells experimental question 4m nacl: the solution will make the elodea plant cell shrink, because there seems to be a high solute concentration.
Hypothesize what will happen to the cells of the elodea in these environments record your hypothesis on your data sheet while the elodea reacts to the above conditions, continue with the following activity. Brownian movement, 2 simple diffusion, 3 osmosis in elodea, 4 osmosis in potato cells, 5 osmosis in germinating radish seeds) each of these exercises should have all of the following elements, with the appropriate heading.
Osmosis in potato cells create a hypothesis for the experiment described below obtain a leaf of elodea and place it on a blank microscope slide. Trouble shooting and cleanup tip: while running the osmosis/diffusion lab today, my students made an interesting discovery the iodine solution reacted with the glucose test strips (carolina biological osmosis lab replacement kit) and turned a color indicating a positive glucose reaction. Diffusion and osmosis as they relate to the living cell (and its membranes) if you have questions about the science of diffusion and osmosis please consult your textbook and/or your instructor. Investigating diffusion and osmosis reasoning (why you corrected the hypothesis the way you did): elodea leaf or spirogyra plasmolysis experiment table 3.