Lab Report
Diffusion & Osmosis Experiment
Sydney Mask
INTRODUCTION All cells in the human body are surrounded by a plasma membrane made up of lipids and proteins which form a barrier. The proteins and lipids in the membrane occupy different roles. The lipids create a semipermeable barrier and the proteins are part of a cross membrane transport. To pass through the membrane a substance goes through a transport known as diffusion. Diffusion is movement of molecules from a high area of concentration to an area of low concentration. There are two different forms of diffusion. One example of diffusion is known as simple diffusion, an unassisted movement of dissolved substances through a selectively permeable membrane (Marieb pg. 54). The
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More specifically for the experiment we will need four deshelled eggs, four beakers and distilled water with a certain percentage of sucrose, a timer, and a scale to weigh the eggs. Using the process of osmosis, we will determine the weight of the eggs after being soaked in the solution. The four beakers each had distilled water in them with sucrose but all contained different amounts. One beaker contained 0% sucrose. The other beakers contained 10%, 40%, and an “unknown” amount of sucrose. Before placing the eggs into the solution, we are to weigh each egg separately to the nearest 0.1g and record this in table. Once that step has been completed, we then place one egg in each of the beakers separately that was marked with the amounts of sucrose. At fifteen-minute intervals, remove the deshelled egg from the water inside the beaker and wipe off all the excess water. After that process has been completed, we will weigh each egg separately to see if they have gained or lost their mass/weight. Once each egg has been weighed accurately, the recorded data is placed in the table provided. This step goes on for an hour. The deshelled eggs in this experiment will increase in mass in the different types of distilled water. This lab session provided the class with the evidence that diffusion and osmosis occurs within the different types of solutions.
RESULTS
In the rubber egg lab also known as the osmosis lab, I first measured the circumference of the egg which was 6 inches. The egg had no cracks and was hard. I placed the egg in the vinegar and within seconds the egg started to bubble. These bubbles were carbon dioxide. After 72 hours the shell of the egg had started to dissolve or flake. This would be considered passive transport as the vinegar diffused across the egg shell without any force. Seventy-two hours into the experiment the membrane was exposed, and had a circumference of 8 inches. Before the egg had a shell and you couldn’t see through it but once the vinegar acted as an acetic acid it broke down the shell and left a yellow membrane that felt like rubber this is an example of diffusion. I then placed the egg in another container and put corn syrup over the egg for 24 hours. The egg had shriveled and shrunk, the water had left the egg and went into the syrup and that is what caused the egg to shrink. The corn syrup is essentially pure sugar with very little water so the osmotic pressure is very low. I then placed the shriveled egg in water and waited for another 24 hours. After observation the egg had no
Students have grouped together in their Anatomy Lab using three different types of Sucrose Bathing Solutions and three different deshelled chicken eggs. Students will learn the permeability of the cell membrane by studying the ability of a shell-less chicken egg to absorb the various sucrose bathing solutions. Students can see how membranes can regulate a cell’s interaction with its environment. The deshelled egg is semi-permeable, meaning that some molecules easily move across the cell membrane, some cannot. A cell membrane can transport materials through two general forms: Simple diffusion and Facilitated diffusion. Principles of Medical Physiology states “Facilitated diffusion, it is generally much faster than simple diffusion. Glucose and other large uncharged hydrophilic molecules have extremely slow rates of simple diffusion across the lipid bilayer but they cross the membrane much faster through facilitated diffusion.” Osmosis can be defined as the
Discussion: In part one, data was collected on the hypotonic, hypertonic, and isotonic concentrations of sucrose, and its effects on the mass of the five shell-less eggs. It was found by calculating the change in mass (see equation 1) during the ten minute intervals, and the percent change of mass (see equation 2), that the forty percent hypertonic sucrose caused the most and quickest change in mass (Table 1). Therefore, as seen in graph 1, it created the fastest osmosis rate compared to the other solutions. In part two, the forty percent sucrose concentration was used to record the data of the three different temperatures, and the shell-less eggs masses. After the data was recorded, that mass change (see equation 1), and percent mass change (see equation 2) was calculated. The second data table showed the decreasing masses and the percent change in mass. Then graph two showed the decreasing percent change in mass in the hot, room temperature and cold solutions.
The solutions are 0% sucrose, 10% sucrose, 20% sucrose, 30% sucrose, 40% sucrose and an unknown sucrose concentration. We then weighed each egg separately to the nearest gram in order to have an initial starting weight to compare to the results throughout our experiment being conducted. The eggs were then placed in each beaker for 12 intervals at a time. After every 12 minutes the eggs were taken out and weighed to see if the weight of the egg changed. With a total of five intervals (12, 24, 36, 48, 60) the steps were repeated till the egg had reached the total time of 60 minutes. The changes in weight of the eggs were then added into a data table showing the weight of the chicken eggs in grams vs. the time in minutes. In a second data table the weight changes (g) vs. time (min.) between the eggs were taken and used the difference from each time and subtracted it from the initial
The primary purpose of the lab was to test and observe the effects of the process of osmosis on decalcified eggs. Before the process, the initial weights of the eggs were taken and noted. Two eggs were then immersed in a deionized water solution. The same was repeated to the other two solutions of 20% and 40% sucrose. The weights of the eggs were measured after 15 minutes to note the change in mass due to osmosis and again after 60 minutes to take the final measurement. Overall, while some human error might arise in the weighing process, care was taken in handling the eggs and during the weighing process. As such, it was found that the eggs behaved as predicted. It was found that the eggs placed in the hypertonic solution lost
Purpose: The purpose of this lab is to familiarize you with osmosis and, specifically, what happens to cells when they are exposed to solutions of differing tonicities.
The Osmosis and Diffusion lab was conducted to provide us with information on how built up mucus affects those conflicted by the recessive genetic disease, Cystic Fibrosis., due to a mutation to the membrane regulating chloride (Cl-). This mutation prevents the Cl- from leaving the cell causing the amount of sodium (Na+) in epithelial cells, which results in extreme mucus on the lungs and airways causing this disease to be fatal if not treated but treatment does not equate to a long lifetime. During the lab we took the data from three parts: Diffusion, Osmosis in an Elodea Cell, and finally the Role of Osmosis in Cystic Fibrosis. During Part 1 we looked at diffusion across a semipermeable membrane for starch and glucose, which resulted in both having a negative solution when placed in a semipermeable membrane. Then we looked at osmosis in the Elodea Cell to watch for the occurrence of Plasmolysis, when a cell’s plasma membrane pulls away from the cell, and how a plant cell is affected by both hypertonic and hypotonic solutions. Finally, we observed the role of Osmosis in Cystic Fibrosis using dialysis bags to represent a normal cell and a Cystic Fibrosis cell with the normal containing 1% NaCl while the Cystic Fibrosis bag contained 10% NaCl. After we ran the experiment, we looked at the Percent Change in Mass and compared them after 30 minutes. We found that Cystic Fibrosis cells didn’t change mass as much as the normal cell ending with a change in mass over -1%. The
The hypothesis states that if the solution is hypotonic the results will decrease, if the solution is hypertonic the results will increase and if the solution is isotonic the solution will vary and or remain constant. In order to test the predictions of the hypotonic, hypertonic, and isotonic hypothesis for the solution made during the study, four samples of sucrose were taken and placed into two different beakers each containing a different concentration. Then dialysis tubing A was placed into beaker 1 with B, C, and D placed into beaker 2 for 45 minutes and weighted at 15 minute intervals. My finding in the study was that each of the four samples changed from their initial weight and for the most part accurately proved the hypothesis.
The purpose to this experiment was to study the effect of osmosis in de-shelled chicken eggs in different percentages of sucrose solutions. Osmosis is the process, in which, water moves across a differentially permeable membrane. The eggs were soaked in vinegar to remove the outside hard shell but still leave the egg in its membrane. By placing the six de-shelled in different sucrose solutions, we tested the rate of osmosis. The eggs were placed in the solutions for an hour and weighed in fifteen minute intervals. Then, each weight was recorded and graphed. The results showed that the egg in the water solution gained the most weigh and the only other egg that gained a little weight was the one in the 10% solution. All the other eggs in the different solutions lost weight, even the unknown solution. According to the results the egg that was in the distilled water solution gained weight because it is the hypertonic solution. All the other eggs lost weight because they were placed in hypotonic solutions with different concentrations of sucrose. The egg that was placed in the higher concentration of sucrose lost the most weight. So, the higher the concentration of sucrose, the more water the egg lost.
An egg has a semi-permeable membrane, thus processes like osmosis could occur. Osmosis is the movement of water molecules from an area of higher water concentration to an area of a lower water concentration. Osmosis is important, especially for living organisms, as they help distribute nutrients in the body. An egg’s mass would change when it is soaked in different substances. The goal of this experiment was to investigate how an egg changes through osmosis. This experiment was done to show how substances affect the mass of an egg. To start off, an egg’s mass was measured by putting the egg in a beaker then placing it on a mass scale. The beaker was then filled with vinegar and left alone for twenty-four hours. After a day, the egg was taken
Osmosis is defined as the tendency of water to flow through a semipermeable membrane to the side with a lower solute concentration. Water potential can be explained by solutes in a solution. The more positive a number is more likely it will lose water. Therefore should water potential be negative the cell the less likely it will lose water. In using potatoes the effects of the molarity of sucrose on the turgidity of plant cells. According to Clemson University, the average molarity of a White potato is between .24 M and .31 M when submerged in a sorbitol solution. This experiment was conducted with the purpose of explaining the relationship found between the mass in plants when put into varying concentrations of sucrose solutions. Should the potatoes be placed in a solution that contains 0.2M or .4M of sucrose solution it will be hypotonic and gain mass or if placed in .6M< it will be hypertonic and lose mass instead. Controlled Variables in this lab were: Composition of plastic cups, Brand of Russet Potatoes, Brand of Sweet Potatoes and the Temperature of the room. For independent variable that caused the results recorded it was the different Sucrose concentrations (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M). The dependent variable was the percentage change from the initial weighs to the final. The cup with .4 molarity was the closest to an isotonic solution and was used as the control group for the lab. Water potential is the free energy per mole of water. It is
Diffusion and Osmosis Experiment with a Shell-Less Egg After Three days of Testing Methods with Water and Corn Syrup
Diffusion is an automated process by where the levels of oxygen, water and carbon dioxide pass over a ‘semi-permeable membrane’ between the walls of the cells and blood vessels to create a level environment. This membrane only allows these three elements to pass whilst retaining other elements such as blood cells, hence semi-permeable. The high concentration on one side of the cells transfers through this membrane until the level is equal on both sides.
Osmosis is a special type of diffusion. It is the diffusion of water across a semipermeable membrane which is a membrane that is freely permeable to water but is not freely permeable to solutes, the water moves from a dilute solution to a more concentrated solution (Karp, 2010). Both diffusion and osmosis are passive transport, energy is not used in the transport. In osmosis water moves across a membrane toward the solution of greater concentration, because the concentration of water is lower there (Martini and Bartholomew., 2007).
4.15. The purpose of this investigation was to use our knowledge on osmosis and diffusion and apply it to a de-shelled egg and see how it reacts being submerged in a sodium chloride solution. The hypothesis was that the egg would expand and increase in both size and weight this is proven correct in the table of