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The membrane of an egg is composed of keratin (a type of protein), which Is semipermeable. This means only certain materials will be allowed to enter and exit through the egg’s membrane. The purpose of this experiment Is study the process In which water molecules pass the egg membrane, osmosis. This experiment also gives Insight on how other ‘semipermeable membranes’ work, Ilke a model for other membranes similar.
If 3 eggs are Immersed In 3 different solutions- salt, sugar, & tap water- then the membrane of the egg will conduct osmosis of water Into the eggs. Materials 3 plastic cups graduated cylinder 3 raw decalcified eggs 100 mL of tap water 100 mL of syrup 100 mL of salt solution welghlng boat electronic scale paper towels safety goggles lab apron Procedures 1. Slip on the lab apron and the safety goggles. 2. Grab a plastic cup and label it with one of the solutions. Set it aside. and record your observations on a data table. 5.
Place the weigh boat on the electronic scale. 6. Reset the scale. 7. Place the egg on the scale & record the mass on the table. 8. Slowly roll the egg into the plastic cup. 9. Measure 100 mL of the solution (the one you labeled on the cup) and gently pour the solution over the egg. 10. Observe the egg currently immersed in the solution and write the observations on the data table. 11. Cover the cup with foil. 12. Repeat steps 2-12 for the remaining two solutions. 13. Store all 3 cups in a cool place for 72 hours. 14. Peel off the foil. 15.
Carefully, drain the liquid from the cup. 16. Make and write observations about the egg. 17. Dispose of the egg properly, in the trash can. Experimental Set-up Results Solution Type Initial Mass Salt Solution 73. 72 g 84. 70 g Initial: Final: Sugar Solution 81. 3g Tap Water 85. 1 g Observations Initial: slightly bloated; membrane is white & crackly; a visible orange ‘glow of yolk; cold; texture is not smooth, not rough, but ‘sandpapered’ down Final: water level is about the same; egg is bloated; not much change in appearance besides size Analysis
The purpose of this experiment was the study of osmosis, which in this specific experiment, is the process in which water molecules pass the egg membrane. If 3 eggs are soaked in sugar solution, salt solution, and water solution, then the eggs will experience osmosis into the membrane. This hypothesis is proven true by the experiment conducted. The data shows only increase in mass of the egg (water had left the cup and entered the egg through osmosis). The salt solution showed less increase in mass than the approximately 18% of mass the sugar solution and tap ater gained.
Nevertheless, the egg immersed in the salt solution also showed increase in mass. The difference in group results and class results indicate some possible error in conducting the experiment and recording the results.