Osmosis Lab Report Sample

Osmosis Lab Report Paper The progress in which a cell is in its balanced state is called equilibrium. Diffusion is a functioning way for cells to reach their equilibrium. Equilibrium is reached by controlling what enters and exits the cell through a cell membrane that selectively filters molecules by slowing down their movement, allowing them to pass through, or not allowing them to pass through the membrane. Diffusion and osmosis go hand-in-hand. Osmosis is generally the same as diffusion, however, deals solely with water. Osmotic pressure is the pressure of a solution against a semi-permeable membrane to prevent water from flowing into the membrane. In this lab, we are going to study ethnicity; ethnicity is the measure of this osmotic pressure and is the differential of pressure twine two solutions separated by a selective membrane. To help identify the relative concentrations of solute particles of different solutions, we must understand that there are three possible differences in concentrations between a cell and its environment. The terms hypotonic, hypersonic, and isotonic are used in referring to the identification of the possible relative concentrations. The first term, hypotonic, is the solution that contains lower concentrations of solute particles, which means that the concentration inside the cell is greater than the concentration outside. A hypotonic solution causes the cell to swell in size. The second term, hypersonic, is the solution that contains higher concentration of solute particles, which means that the concentration of the cell is less than that outside the cell. We will write a custom essay sample on Osmosis Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Osmosis Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Osmosis Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer A hypersonic solution causes the cell to shrink in size. Lastly, the third term, isotonic, is the solution in which the cell stays the same, which means concentrations inside and outside the cell are equal, so water enters and exits the cell equally resulting in equilibrium. OBJECTIVE: The objective of this lab is to identify each egg in its relative concentration of solute particles of different lotions as either a hypotonic, a hypersonic, or an isotonic solution based on the change in each eggs mass from time 0 to time 60 in minutes. With that, ones aim is to find the concentration of the unknown solution given by the instructor, and to identify at which point an isotonic solution occurs. HYPOTHESIS: If an egg is placed in a hypotonic solution, then the egg will increase in water mass and swell. If an egg is placed in a hypersonic solution, then the egg will decrease in water mass and shrink. MATERIALS AND PROCEDURE: In order to proceed in the experiment, the following materials were obtained: 6 e-shelled eggs Scale Weighing trays Paper towels Timer Beakers of solutions containing 0%, 10%, 20%, 30%, sucrose and an unknown solution To begin this experiment, first each group was given six De- shelled eggs, a scale, weighing trays, paper towels, a timer, and beakers of solutions containing 0%, 10%, 20%, 30%, 40% sucrose, and an unknown solution. To get this lab started, the scale was first plugged in. Once the scale was plugged and ready for use, we placed the weighing trays on the scale and tarred it to zero, so that the trays weight wouldnt have any impact on the weights of the eggs. After the weighing trays were tarred, each egg was placed atop the trays and the initial weight of the eggs were measured and recorded in lab notebooks under results in Table 1 Chart. Correspondingly, each of the six De-shelled eggs were placed in the various solution concentrations, 10%, 20%, 30%, 40% sucrose, and an unknown solution. After being merged in the various concentration solutions for fifteen minutes, the eggs were then taken out of the beaker-filled solutions, patted dry with paper towels, and weighed. The new weights of the eggs were again recorded in lab notebooks under Table 1 Chart. This process was repeated in fifteen minutes intervals from time zero to time 60 minutes. Thereafter, the values in the chart for Table 2 was calculated by subtracting the weight at any time intervals 15, 30, 45, or 60, from the initial weight to get the total change with respect to time. Osmosis Lab Report Sample Osmosis Lab Report Paper The resulting weights were recorded and the data was graphed. We then could draw conclusions on the lab. Introduction Diffusion and Osmosis are two concepts that go hand in hand with each other. Diffusion is simply described as the movement of a substance from a region of high concentration to a region of low concentration. In another words, the substance will move down its concentration gradient which is the region along which the density of a chemical substance increases or decreases (Campbell Biology pig. 132). If you understand the concept of diffusion then osmosis is a very simple process. It can be defined as the diffusion of water across a permeable membrane. Osmosis can be cellular or artificial, so even though we are creating artificial cells in this lab, it is still considered to be osmosis. During osmosis, a solvent is trying to get through a selectively permeable membrane to make the concentration of that solvent the same on both sides of the membrane. The rate of osmosis depends on the type of environment the cell is in. There are three different environments that a cell can find itself in, a hypersonic environment, a hypotonic environment, or an isotonic environment. We will write a custom essay sample on Osmosis Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Osmosis Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Osmosis Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The environment a cell is in will determine its tonic which is the ability of a surrounding solution to cause a cell to gain or lose weight (Campbell Biology pig. 133). In a hypersonic solution, the cell will lose water, shrivel up, and most likely die (Campbell Biology pig. 133). The reason this happens is because there is a higher concentration of water in the cell then there is in the environment the cell is in. Like I said before, water travels down its concentration gradient from high concentration to low concentration. So the water inside the cell will cross the membrane and enter into the solution outside the cell and it will continue to do this until the concentration inside the cell membrane and outside the cell membrane are equal. The opposite of this would be if the cell was in a solution that is hypotonic to the cell. In a hypotonic solution, Water would enter the cell faster than it leaves and the cell will swell up and else (burst) (Campbell Biology pig. 134). This will also cause the cell to die. Both a hypersonic and hypotonic solution are very harmful to cell and in most cases will cause the death of the cell. A solution that a cell wants to be in is an isotonic solution. If the concentration of water in the cell and in the surrounding environment is equal, there will be no net movement of water across the membrane and therefore the cell will not shrivel up or swell up. ). An experiment has been conducted to find out whether or not osmosis is occurring by using artificial cells made of dialysis tubing. To test this hypothesis the experiment will show the change in weight of each artificial cell across a 90 minute time span. The experiment will also show which type of environment (as previously stated) each cell is placed in and taken out of to be weighed. Materials and Methods This experiment will look at the effects of various sucrose concentrations on the rate of osmosis in artificial cells made up of dialysis tubing. To begin the experiment one strip of dialysis tubing will be filled with mol of tap water, the second will be filed with mol of 20% sucrose, the third with mol of sucrose, the fourth with mol of 60% sucrose, and the fifth bag will be filled with mol of tap water also. The dialysis tubing will be clamped at one end in order to fill it and then clamped at the other end to seal the filled bag. If the bag is not soft and floppy, the experiment will not work. Blot a bag with a paper towel to absorb the moisture and weigh it, if this blotting process is not done it could interfere with the weight readings creating inaccurate information. After the bags of the solutions are prepared, they will be placed into five different beakers with different solutions. Beakers 1-4 will be filled with tap water and the fifth beaker is filled with 40% sucrose and water. Fill each beaker with just enough water or solution so that the bag is covered and place the bags in the beakers simultaneously and record each time. Every 10 min the bags are to be taken out, looted, and weighed again before returning them back into their respective beaker for another 10 min. The process is repeated until you have reached 90 min. The weights should be recorded in grams (g). Results Table 1 shows the contents of the bags and the content of the concentration it was submersed in. Bags 2-4 each contain a solution of both sucrose and water. These bags were each put into beakers containing hypersonic solution. These bags gained weight over time because the water moved from its high concentration inside the beaker to the low concentration inside the membrane of he artificial cell, the membrane being the bags that consisted of dialysis tubing. The water will continue to move through the pores of the dialysis tubing into the concentration of water is the same in the beaker as well as inside the artificial cell. Bag 1, consisting of water, was also put into a breaker containing water. The weight of this bag remains the same because it was placed in an isotonic solution, where the concentration of water was the same. Because of this, osmosis does not occur. The last bag (bag 5) contained only water whereas the beaker it was immersed in was a solution of sucrose. The solution is a hypersonic solution because the concentration of water was higher inside the artificial cell then outside the cell membrane, inside the beaker. Because of this, the weight of bag 5 decreased as time went on because water was constantly leaving the bag through the pores of the dialysis tubing in an attempt to make the concentration of water equal inside and outside of the bag. As you can see from the results plotted in Graph 1, the bags that were put into a hypotonic solution gained weight over time, whereas the bag that was put into a hypersonic solution lost weight over time. Conclusion/ Discussion As you look over the results of this experiment it is clear that indeed osmosis does occur in an artificial cell with a permeable membrane made of dialysis tubing. As the data shows, the artificial cells that were placed in hypotonic solutions had a gain in weight, the artificial cell that was placed in a hypersonic solution lost weight, and the cell placed in an isotonic solution stayed the same. The amount of weight gained or lost depends on how concentrated the solutions are, and this did not show in our results (Graph 1). The rate of diffusion or osmosis is dependent on such factors as temperature, partial size, and the incineration gradient (General Biology I Laboratory experiments and exercises pig. -1). The cell containing 60% sucrose should have ended up being heavier than the cells containing 20% and 40% sucrose, but an error must have occurred during our lab that changed the data that was collected. All in all, the results still prove our hypothesis that osmosis does occur in artificial cells. This means that when an artificial cell is placed in a hypotonic solution, it will gain weight. If an artificial cell is placed in a hypersonic solution it will lose weight, and if it is placed in an isotonic solution it will stay the same. Osmosis Lab Report Sample Osmosis Lab Report Paper Living organisms tend towards balance with their environment. Cells achieve this through diffusion. This is the random movement of solutes from an area of higher concentration to lower concentration. Osmosis is a special case of diffusion. Osmosis is the movement of water through a selectively permeable membrane. During osmosis, water molecules diffuse through the membrane from a region of higher water potential to lower water potential until equilibrium is reached. (1) In this lab, the idea was to see how the mass changed as osmosis occurred and water flowed into or out of the potato. Hypothesis: Our hypothesis was If the sucrose levels in the water are high, then the osmosis will occur at a less frequent rate. However, if the concentration of the solution is less than that of the potato (like in distilled water), then the mass of the potato will increase. Independent and Dependent Variable: The independent variable in this lab was the sucrose concentration. The dependent variable in this lab was the mass of the potato slice. Control Group and Controlled Variables: The control group included the cup that was just water, no sucrose. To ensure hat the experiment was valid, we had to control several things to make SUre that the conditions and results would be the same. These variables were the time the potato strips were in the solution, the amount of solution the potato strips were immersed in, the size of the potato strips, the types of cups, and the temperature in the room. Materials: In this lab the materials that we used were potatoes, sucrose solution, balance scale, paper towels, plastic cups, and a plastic knife. Procedure: First, we were to prepare a stock solution of 1. MM sucrose. We will write a custom essay sample on Osmosis Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Osmosis Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Osmosis Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Then we repeated these past steps for the other sucrose solutions. After each set of potato slice was soaked for 25-30 minutes, we removed them from the cups and blotted them gently on a paper towel. Finally, their final mass was recorded and we were able to calculate the percent change in mass. Data Collection: observed that the potatoes that showed a positive change in mass looked more swollen, and the potatoes that showed a negative change in mass looked more shrunken. All of the potatoes, however, were soggy and slimy. Conclusion: Based on the lab results, you are able to conclude that the more sucrose a incineration has, the less osmosis takes place. Also, after a certain amount of sucrose concentration, osmosis begins to work in the opposite way. One is able to conclude this because in the graph above, the first few intervals show that overall the potato strips gained mass, meaning that more water went into the cells, but then they begin losing mass, meaning water left the cells. In the hypothesis we said that as the sucrose concentration increased, the mass of the potatoes would decrease and it did. We also said that when the concentration of he solution was less than the concentration of the potato, the mass would increase, and we can see an increase in mass for concentrations of 0. 0 M sucrose (distilled water), 0. 2 M sucrose, and 0. 4 M sucrose. From this, we can conclude that the potato has a sucrose concentration of greater that 0. 4 M. Osmosis occurs when there is a concentration gradient, and water flows from a high to low concentration. In solutions that had no sucrose, there are high concentrations of water, especially when compared to a potato, so water would go into the potato. While solutions with high sucrose concentrations had low water concentration, and so water would leave the potato and try to balance the amount of sucrose. The method of this experiment had a few issues, especially because we had to change parts of the procedure to adapt to the classroom setting. Instead of each group testing five of their won potato slices, we shared answers. This caused problems and limitations because each potato slice may have been very different in size, causing there to be different rates of osmosis. Osmosis Lab Report Sample Osmosis Lab Report Paper The result was that the more sucrose in the bag, the greater the final mass. Introduction: The reasons for doing this lab are so that we can learn about osmosis with a model similar to a cell and so that we can have a better understanding of the process and nature of osmosis. Osmosis is diffusion but with water molecules. A concentration gradient exists and because of this, diffusion of solutes cant happen. Very select things can pass in and out, such as water, oxygen, and carbon dioxide. In this situation, a large molecule of starch would be dissolved in eater because the molecule is too big to fit through the membranes pores. Since the membrane in permeable to water molecules, it causes the water molecules to diffuse from an area of high water concentration to an area of low water concentration. This movement itself is osmosis. To determine if the concentration of solutions is isotonic (solute is equal to the cell), hypotonic (solute is lower outside of the cell), or hypersonic (solute is higher outside of the cell), you measure the total amount of particles in the solution. We will write a custom essay sample on Osmosis Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Osmosis Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Osmosis Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer My hypothesis is: if the alkalis tubing that is filled with sucrose solution and fully emerged in a beaker of distilled water, then the water will seep into the dialysis tubing and the tubing will become a greater mass. The independent variables in this lab are the beakers of distilled water, and the amount of sucrose (0. 2-1 MM). The dependent variables are the final mass of the bag, the change in the mass of the bag, and % change in the mass of the bag. The control is the amount of sucrose solution and distilled water (ml). Methods and Materials: 1. Time Period: * One class period (approximately Air and mini) 2. Subject Studied: * % Change in the mass of the bag 3. Materials Used: * 6 beakers * 1 funnel * CACM soaked dialysis tubing * 12 pieces of string * Balances * Distilled water * Mimi 0. MM Sucrose Solution * 1 mom 0. MM sucrose solution * Mimi 0. MM Sucrose Solution * 1 Iron 0. MM Sucrose Solution * Mimi 1 -MM Sucrose Solution * Mimi Distilled water 4. Procedure: * Number the beakers 1-6. * Gently rub the dialysis tubing between your fingers to open the tubing up. Tie one end of the tubing with a piece of string and fill the tubing with water to test and see if it leaks. Empty out the tubing. Repeat for all six of the dialysis tubing. * Use the medicine cup given to you to measure out ml of each of the solutions and put into its corresponding dialysis bag: Bag to be put in cup # Solution to be put in bag I 1 | Distilled Water I 2 | 0. MM Sucrose I 3 | 0. MM Sucrose I 4 | 0. MM sucrose I 5 | 0. MM Sucrose I 6 | 1. MM Sucrose I * Rinse out the medicine cup between solution uses. Dont forget to gently squeeze out the excess air in bags. * Tie off the other end of all dialysis tubing with a piece of string. Run the bag under water for just a moment. After, gently squeeze the bag to check if it is leaking. If theres a leak, be sure to retie it tightly/ tighter. * Dry the outside of the tubing with a paper towel and use the balance to measure the mass of all 6 bags separately. Record the masses. * Place the bags into their corresponding beakers and fill the beakers with distilled water enough that the dialysis tubing is completely submerged in the distilled water. Wait 30 minutes to let osmosis happen. * After the times up, remove the bag from the beakers, wipe off excess liquid gently, and record the bags masses separately. Record the masses. For all solutions, subtract the initial mass from the final mass to get the change in mass of the bag. Record the positive or negative results. * For all solutions, take the results from the last step and divide it by the initial mass, then multiply it by 1 00 to get the percent change in mass for each bag. Record the percentages. * Calculate the class average % change in mass for each solution. Record results. Results: Discussion: The data is stating that the mass has risen after the 30 minute time period. Osmosis has occurred, because the water molecules have diffused into the dialysis tubing. I have concluded that my hypothesis was correct, since the date reinforces that the mass is greater after being put into the beakers of distilled water. Some sources of error couldve been when we found out that one of our bags was leaking, another would be when the sucrose solution was spilled out of the dialysis tubing and it got all over the outside and we mightnt not wiped off all of the solution off. More errors could be not covering the bags completely with distilled water or not leaving the bags in the beakers for exactly 30 minutes. Some modification that could be made to the lab to improve it could be having he same length of tubing/string, and stopwatches for timing 30 minutes exactly. Also, putting the tubing in at the same time so the timing is all on point could help with accuracy. Questions that came to mind during this lab were; Is the timing correct and how much will it affect the results? Are the solutions of sucrose sitting in the bags waiting while we fill the others going to change/be affected? Are any of the bags leaking or have any excess solution outside of the bag?