Egg Macromolecules Lab

In this lab we asked the question “Can macromolecules be identified in an egg cell?” We found that the egg membrane tested positive for lipids. After adding the solution Sudan III, the indicator for lipids, the egg membrane turned orange, showing that it contained the macromolecule of lipids. The amount of lipids that showed up was rated a 7 on a scale of 1 to 10 when looking at how dark of an orange the membrane turned. Based on what we learned from previous vodcasts about cells, specifically “Intro to Cells,” the cell membrane is made up of lipids, specifically phospholipids. This evidence, coming from both the experiment and my previous knowledge from the vodcasts, supports our claim that the egg membrane tested positive for lipids, because membranes, including the egg membrane we tested, are made up of lipids.

In this lab, when testing the egg white, we found that it tested positive for monosaccharides. After adding the Benedict’s solution, the indicator for monosaccharides, the egg white turned from blue to green, showing that it had monosaccharides. We rated it a 10 out of a scale of 1 to 10 when again, looking at how dark the color was. Based on what we learned in previous vodcasts, again specifically “Intro to Cells,” we learned that cell walls are rich in carbohydrates, meaning that monosaccharides and polysaccharides are found in the cell wall. This data and evidence supports our claim that the egg white tested positive for monosaccharides, because in an egg, the egg white acts as the cell wall, meaning that the egg white will test positive for monosaccharides.

In addition to testing the egg membrane and the egg white, we tested the egg yolk in this lab, and we found that it tested positive for proteins. After adding both Sodium Hydroxide (NaOH) and the Copper Sulfate (CuSO4), the indicator for proteins, the yolk in the test tube turned from a blue color to a purple color, indicating that proteins were very evident in the egg yolk. Based on what we learned in again previous vodcasts, specifically “Into to Cells,” we learned that proteins are found in many different organelles in the cell. In addition based on previous knowledge, that the egg uses the yolk to develop into a chicken using structural proteins. This data and evidence supports our claim that the egg yolk tested positive for proteins, because the egg yolk contains many structural proteins.

While our hypothesis was supported by our data, there could have been errors due to the amount of the indicator solutions was used and the time it was left out. We were instructed to put 3 to 5 drops of the indicator solution into the part of the egg we were testing. This leaves it up to the scientist to decide how many drops they will put. Since there were four different people doing the experiment, the number of drops could have been different leading to results that aren’t as accurate as they could have been. This could have affected the results because the colors could have been darker, leading to different and less accurate numbers, regarding our quantitative observations. In addition, the ratings weren’t as accurate as it could have been, as there wasn’t a clear understanding between the 4 of us doing different parts of the experiment what each number meant on the scale of 1 to 10 when looking at how dark of a color appeared due to the drops of indicator solution in either the membrane, the yolk, or the egg white. This could have affected the results because a 1 could have been the same as someone’s 4, making the data invalid. Due to these errors, in future experiments, I would recommend doing the experiment only after discussing what each number in the scale of 1 to 10 means, and I would also recommend having a consensus regarding how many drops of the indicator solution we would have.

This lab was done to demonstrate and show us what macromolecules and in what concentration are found in different parts of the cell. From this lab, I learned that most of the macromolecules are found in most of the parts of the cell, but there is a very high concentration of lipids in the egg membrane, a very high concentration of monosaccharides in the egg white, and a very high concentration of proteins in the egg yolk, which helps me understand the concept of the location and job of the organelles and parts of the cell. Based on my experience from this lab I could apply this to other situations because this lab is able to tell me what I get from eggs in terms of carbohydrates, lipids, and proteins. This lab is able to give me a rough estimate on how much of each macromolecule is found in the egg, which will help me customize my meal after eating an egg, so I can get the right amount of protein and carbohydrates.