Tuesday, October 27, 2015

Egg Diffusion Lab

10-7-15
In this lab, we tested eggs to demonstrate how a cell’s internal and external environment changes. First we soaked two eggs in vinegar, which dissolved the egg shell so we could look into the membrane. After measuring their initial circumferences and masses, we placed one egg in deionized water and the other in sugar water. After 2 days we looked at the eggs again and most of the eggs in water burst while the eggs in sugar water shriveled up.
According to the class data, the egg in sugar water became significantly smaller the mass shrinking by about 50%  and the circumference shrinking by about 20%. The reason this happened was because the water that was inside the cell went out of it to dilute the sugar that was surrounding the egg. The solvent in this solution was the water and the solute was the sugar.
When a cell’s environment changes it either grows; like in a hypertonic solution, or shrivels up; like in a hypotonic solution. When the egg was in vinegar, it disintegrated the shell and but the egg stayed the same size since it was in an isotonic environment. When the egg was in water it also grew since the water diffused into the egg. While the egg was in the sugar water it shriveled up and shrunk significantly since it sat in a hypotonic solution for so long. The water inside each cell passively diffused across the membrane, from an area of high to low concentration.
This lab mainly helped demonstrate the differences between isotonic, hypotonic, and hypertonic solutions. We experienced an isotonic solution with the vinegar, hypertonic with water, and hypotonic with the sugar.
In life, these applications are used daily by different people. Fresh vegetables are drizzled with water to keep them hydrated and healthy. The water goes inside the cells of the vegetables keeping them big and juicy. Salt is used to de-ice roads because the salts cause the water to diffuse out of the ice, leaving behind a driveable road. But, if there are plants alongside the same road it could do harm to them because the salt will suck out the water it needs to grow and flourish since salt and water is a hypotonic solution.
Based off this experiment I would want to dig deeper to the cellular level and test individual cells under a microscope in these solutions. I would want to see how each organelle is affected rather than a whole egg.
Class Data: Control (DI water)                            %change
Group#
1
2
3
4
5
6
7
AVG
Mass
N/A*
N/A*
.74
.37
.45
N/A*
6.95
1.8
Circumference
N/A*
N/A*
1.2
1.7
0
N/A*
14.37
4.3
*Egg burst

Class Data: Sugar Water                            %change
Group#
1
2
3
4
5
6
7

Mass
-46.70
-52.80
-52.60
-49.70
-41.71
-39.58
-47.70
-47.25
Circumference
-22.40
-18.75
-26.30
-26.60
-32.35
-21.21
-13.00
-22.94

IMG_1978.JPG

Tuesday, October 6, 2015

Egg Macromolecules Lab Conclusions

In this lab we asked the question, “Can macromolecules be identified in an egg cell?” After testing the egg membrane, we found all the macromolecules we tested for, including lipids, proteins, monosaccharides, and polysaccharides. In the yolk we found lipids and the egg white we again contained lipids, proteins, and monosaccharides. On a scale of one to ten, monosaccharides’ existence were a 5 in the membrane and a 2 in the egg white. We knew this because the solution of the egg part and benedicts turned green. Polysaccharides in the membrane were a 7 out of 10 because the color of the iodine mixture turned from light to dark brown. Proteins were a 5 in the membrane and scored a 3 in the egg white because the sodium hydroxide copper sulfate changed from blue to pink/purple. Finally lipids were found in all of the egg, being a 6 in the membrane, 4 in the yolk, and 2 in the egg white. We knew this after the Sudan III color changed from red to  pink/orange. 
One error that may have caused deterred results was the egg not mixing well with the solution used to test its presence. In some directions it said to mix them and in others it didn’t specify. If this happened, some solutions may have a brighter or lighter color and may be interpreted wrong. Another thing that could’ve gone wrong was putting too much or little solution into the egg filled test tubes which could cause too much or too little color, again leading to misinterpreted results. One way to avoid this is to specifically state in the directions the exact amount of drops to put in and whether to stir or not. Another recommendation would be to have more than one test for each egg part just to make sure the results are true. 
This lab was done to model the existence of macromolecules in cells. From this lab I applied the information we learnt in class to real cells which helped me visualize the concepts. By seeing lipids, proteins, and mono/polysaccharides in the cells I took the information from the vodcasts and textbook about macromolecules and related it to cells in eggs and many other areas and how they exist everywhere. Based on my experience from this lab, I was provided with an application of these foundational concepts, which will help me when the class goes deeper into the structure and function of cells.