Osmosis Egg Lab Report
THE AFFECTS OF DIFFERENT SUCROSE
SOLUTIONS ON OSMOSIS
OF EGG MEMBRANES
A laboratory report submitted for
LE@D Biology 1004
Michele Liveley
Arkansas State University Mountain Home
Mountain Home, AR
September 2013
Osmosis Egg Lab Report
Introduction
Osmosis is the passing of water or other solutions from an area of high concentration of particles to an area of less concentration. The cell membrane is an organelle, selectively permeable, and only allows certain materials to pass through; it can allow smaller molecules to pass while blocking larger molecules. Molecules that are blocked can be moved through active transport, such as, through proteins that are embedded in the bilayer of lipids. …show more content…
(Nave) The figure below shows a plasma membrane and labels its’ components. Figure 1. Image of a plasma membrane bilayer.
(http://eng.thesaurus.rusnano.com/upload/iblock/865/biomembrane.jpg)
Cells are structured with a plasma membrane encasing cytoplasm that houses water, sugars, and proteins. The nucleus, inside the cytoplasm, contains DNA. Cell membranes are organelles composed of mostly phospholipids. They have hydrophilic heads and hydrophobic tails. There are two layers of phospholipids; the heads are polar and line up towards fluid and tails are nonpolar and group together forming two layers. This lipid bilayer is the main construction of cell membranes; it controls the transport of molecules to and from the cell. (The Cell Membrane) The image below shows an example of a phospholipid. Figure 2. Image of a phospholipid molecule.
(http://faculty.stcc.edu/biol102/Lectures/lesson4/lipids.htm)
The purpose of this lab is to investigate activities of the plasma membrane. We will be using decalcified chicken eggs; eggs will be placed in vinegar for three days to dissolve the shell exposing the plasma membrane, to test osmosis through the membrane with different sucrose solutions. The hypothesis is: different sucrose solutions have no affects on diffusion of water through the plasma membrane. We will test the hypothesis using four different concentrated solutions; distilled water will be mixed with 0%, 10%, 20%, and 40% sucrose.
The decalcified eggs will be weighed before and after being put in the solutions. The zero and ten percent solutions are hypotonic, so the eggs should gain weight. The twenty percent solution is isotonic and the weight should primarily stay the same. The forty percent solution is hypertonic, so the weight should decrease. (Muller)
Experimental Procedure Eight eggs are placed in a medium glass bowl and covered in vinegar. (Although, we only need four eggs extras are made in the case some of them break.) The bowl is drained after 1.5 days and new vinegar is added until the eggs are covered. The vinegar is drained 1.5 days after replacing the vinegar. Each egg is rinsed in tap water. The eggs are now decalcified and the plasma membrane is exposed. Next, prepare our solutions of sucrose concentrations. To prepare the 10% sucrose solution, measure 17 ounces of distilled water and stir in ¼ cup sugar. Mix 17 ounces of distilled water and stir in ½ cup sucrose for the 20% solution. Mix 17 ounces of distilled water and stir in 1cup sugar for the 40% solution. The 0% sucrose solution is only distilled
water. Take four clean large clear plastic cups and label them with each of the sucrose solution. Add one cup of each solution to the appropriate cup. Using a kitchen scale, weigh one decalcified egg, write the beginning weight on a cup, and then place the egg in the cup for two hours. Repeat this process until each cup has a weighed egg in its’ solution. After two hours dump the liquid out of one of the cups, be careful not to break the decalcified egg. Weigh the egg and write the final weight on the cup. Repeat this process for each egg in each cup. Next, add or subtract the final weight from the original weight of each of the decalcified eggs. Write the net change on the cup. Fill out chart of initial, final, and net change of weight. Determine if the eggs were hypotonic, isotonic, or hypertonic. If there are unbroken decalcified eggs, this experiment can be produced again to ensure accuracy.
Results
Observations of the eggs 0% sucrose 10% sucrose 20% sucrose 40% sucrose
Decalcified egg weight (in grams)before soaking in sucrose solution
85 grams
83 grams
81 grams
89 grams
Decalcified egg weight (in grams) after soaking in sucrose solution
88 grams
81 grams
78 grams
83 grams
Net change in weight (in grams)
+ 3 grams
-2 grams
-3 grams
-5 grams
Figure 2. Results from egg experiment.
Discussion
We have discovered our hypothesis is false. Different sucrose solutions do have affects on diffusion of water through the plasma membrane. The results clearly indicate the transfer of water through the cell membrane, either by the eggs gaining weight or losing weight. During osmosis solutions of high concentration move to areas of low concentration. Diffusion in the eggs occurs until there is an equal amount of water molecules on each side of the cell membrane. (Muller) The egg with zero percent sucrose is the only one that gained weight; this occurred because the water molecules had a higher concentration in the cup than in the egg. Therefore, water molecules diffused through the plasma membrane into the egg. All the other eggs lost weight because water diffused through the cell membranes into the cups. The concentration of water molecules in the cup had less concentration than the eggs. As the amount of sucrose increased in each solution, the eggs lost more weight by diffusing water molecules from the eggs into the solutions in the cups.
Even though, the original thought was the eggs with zero and ten percent sucrose solution would be hypotonic, the twenty percent solution would be isotonic, and the forty percent would be hypertonic the results prove mostly untrue. The zero percent sucrose solution was the only hypotonic solution and the egg gained weight. The three eggs with sucrose were hypertonic because they gave away molecules and lost weight. The results did not show an isotonic solution.
References Cited
Muller, M. (2003). Diffusion, Osmosis, and Movement Across a Membrane. In University of Illinois at Chicago. Retrieved September 16, 2013, from http://www.uic.edu/classes/bios /bios100/mike/spring2003/lect07.htm
Nave, D. (n.d.). Osmosis, Difussion, and Active Transport. In Georgia State University. Retrieved September 16, 2013, from http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
The Cell Membrane. (2013, March 22). In University of South Dakota. Retrieved September 16, 2013, from http://sites.usd.edu/cell-ebration/the-cell-membrane
SOLUTIONS ON OSMOSIS
OF EGG MEMBRANES
A laboratory report submitted for
LE@D Biology 1004
Michele Liveley
Arkansas State University Mountain Home
Mountain Home, AR
September 2013
Osmosis Egg Lab Report
Introduction
Osmosis is the passing of water or other solutions from an area of high concentration of particles to an area of less concentration. The cell membrane is an organelle, selectively permeable, and only allows certain materials to pass through; it can allow smaller molecules to pass while blocking larger molecules. Molecules that are blocked can be moved through active transport, such as, through proteins that are embedded in the bilayer of lipids. …show more content…
(Nave) The figure below shows a plasma membrane and labels its’ components. Figure 1. Image of a plasma membrane bilayer.
(http://eng.thesaurus.rusnano.com/upload/iblock/865/biomembrane.jpg)
Cells are structured with a plasma membrane encasing cytoplasm that houses water, sugars, and proteins. The nucleus, inside the cytoplasm, contains DNA. Cell membranes are organelles composed of mostly phospholipids. They have hydrophilic heads and hydrophobic tails. There are two layers of phospholipids; the heads are polar and line up towards fluid and tails are nonpolar and group together forming two layers. This lipid bilayer is the main construction of cell membranes; it controls the transport of molecules to and from the cell. (The Cell Membrane) The image below shows an example of a phospholipid. Figure 2. Image of a phospholipid molecule.
(http://faculty.stcc.edu/biol102/Lectures/lesson4/lipids.htm)
The purpose of this lab is to investigate activities of the plasma membrane. We will be using decalcified chicken eggs; eggs will be placed in vinegar for three days to dissolve the shell exposing the plasma membrane, to test osmosis through the membrane with different sucrose solutions. The hypothesis is: different sucrose solutions have no affects on diffusion of water through the plasma membrane. We will test the hypothesis using four different concentrated solutions; distilled water will be mixed with 0%, 10%, 20%, and 40% sucrose.
The decalcified eggs will be weighed before and after being put in the solutions. The zero and ten percent solutions are hypotonic, so the eggs should gain weight. The twenty percent solution is isotonic and the weight should primarily stay the same. The forty percent solution is hypertonic, so the weight should decrease. (Muller)
Experimental Procedure Eight eggs are placed in a medium glass bowl and covered in vinegar. (Although, we only need four eggs extras are made in the case some of them break.) The bowl is drained after 1.5 days and new vinegar is added until the eggs are covered. The vinegar is drained 1.5 days after replacing the vinegar. Each egg is rinsed in tap water. The eggs are now decalcified and the plasma membrane is exposed. Next, prepare our solutions of sucrose concentrations. To prepare the 10% sucrose solution, measure 17 ounces of distilled water and stir in ¼ cup sugar. Mix 17 ounces of distilled water and stir in ½ cup sucrose for the 20% solution. Mix 17 ounces of distilled water and stir in 1cup sugar for the 40% solution. The 0% sucrose solution is only distilled
water. Take four clean large clear plastic cups and label them with each of the sucrose solution. Add one cup of each solution to the appropriate cup. Using a kitchen scale, weigh one decalcified egg, write the beginning weight on a cup, and then place the egg in the cup for two hours. Repeat this process until each cup has a weighed egg in its’ solution. After two hours dump the liquid out of one of the cups, be careful not to break the decalcified egg. Weigh the egg and write the final weight on the cup. Repeat this process for each egg in each cup. Next, add or subtract the final weight from the original weight of each of the decalcified eggs. Write the net change on the cup. Fill out chart of initial, final, and net change of weight. Determine if the eggs were hypotonic, isotonic, or hypertonic. If there are unbroken decalcified eggs, this experiment can be produced again to ensure accuracy.
Results
Observations of the eggs 0% sucrose 10% sucrose 20% sucrose 40% sucrose
Decalcified egg weight (in grams)before soaking in sucrose solution
85 grams
83 grams
81 grams
89 grams
Decalcified egg weight (in grams) after soaking in sucrose solution
88 grams
81 grams
78 grams
83 grams
Net change in weight (in grams)
+ 3 grams
-2 grams
-3 grams
-5 grams
Figure 2. Results from egg experiment.
Discussion
We have discovered our hypothesis is false. Different sucrose solutions do have affects on diffusion of water through the plasma membrane. The results clearly indicate the transfer of water through the cell membrane, either by the eggs gaining weight or losing weight. During osmosis solutions of high concentration move to areas of low concentration. Diffusion in the eggs occurs until there is an equal amount of water molecules on each side of the cell membrane. (Muller) The egg with zero percent sucrose is the only one that gained weight; this occurred because the water molecules had a higher concentration in the cup than in the egg. Therefore, water molecules diffused through the plasma membrane into the egg. All the other eggs lost weight because water diffused through the cell membranes into the cups. The concentration of water molecules in the cup had less concentration than the eggs. As the amount of sucrose increased in each solution, the eggs lost more weight by diffusing water molecules from the eggs into the solutions in the cups.
Even though, the original thought was the eggs with zero and ten percent sucrose solution would be hypotonic, the twenty percent solution would be isotonic, and the forty percent would be hypertonic the results prove mostly untrue. The zero percent sucrose solution was the only hypotonic solution and the egg gained weight. The three eggs with sucrose were hypertonic because they gave away molecules and lost weight. The results did not show an isotonic solution.
References Cited
Muller, M. (2003). Diffusion, Osmosis, and Movement Across a Membrane. In University of Illinois at Chicago. Retrieved September 16, 2013, from http://www.uic.edu/classes/bios /bios100/mike/spring2003/lect07.htm
Nave, D. (n.d.). Osmosis, Difussion, and Active Transport. In Georgia State University. Retrieved September 16, 2013, from http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
The Cell Membrane. (2013, March 22). In University of South Dakota. Retrieved September 16, 2013, from http://sites.usd.edu/cell-ebration/the-cell-membrane