Egg Macromolecules Lab

    In this lab, we asked the question "can macromolecules be identified in an egg cell?" We found, as a group, that the egg membrane has proteins and lipids, the egg yolk had monosaccharides, proteins, and a lot of lipids, and the egg white had a lot of proteins and some lipids. This evidence was from our observations from the different colors that were generated when the egg parts reacted with different solutions, including Benedict's solution, iodine, sodium hydroxide, copper sulfate, and Sudan III. We used these solutions to mix with the different parts of the egg to generate different colors of solutions, in which the color of the solution would determine which macromolecule were present in each part of the egg. We also have evidence from background information of the different solutions from the handout given by Mr. Orre. We knew that if a monosaccharide was present, such as glucose, benedict's solution would turn from blue to orange, depending on its strength, orange being the strongest. If polysaccharides are present, such as starch or cellulose, iodine will turn the solution from brown to black. If lipids are present, Sudan III or IV will turn the solution from red to orange. If proteins are present, sodium hydroxide and carbon sulfate can be added, turning it from blue to purple. We used these different solutions, such that in the end, we were able to conclude which parts of the egg had these different macromolecules in them. Our claim about the egg membrane, which acts as a barrier, letting certain things in and out, contains proteins, so that transport is easier. Our claim about the egg white is that it has a lot of proteins inside of it, because many of these proteins are actually enzymes which break down any pathogens that might pass through the membrane. Our claim about the egg yolk is that it contains a lot of lipids, because similarly to cells, as the chick develops in the egg, the organelles that make up the developing chick has a lot of lipids, so the egg yolk has those lipids from organelles that were made to develop the chick. This data supports our claim, because the solutions turned different colors, just as it was said to do, and we were revealed which parts of the egg contained what, supporting our claim of which egg parts had which macromolecules!

    While our hypothesis was supported by our data, there could’ve been errors due to the fact that some of our egg membrane did not mix in well with the solution, so the solution may not have reacted with the egg membrane, therefore it might've not produced the correct color to identify itself of being positive or lacking the macromolecule thereof. Another possible error was that the egg yolk also contained a lot of the egg yolk membrane, and the egg yolk membrane might be positive of a solution, whereas the egg yolk itself wasn't, so those results would have been skewed, too. I would recommend to have a more sophisticated way to separate the different part of the egg, such that errors of mixing very chemically different parts of the egg could not occur. As a second suggestion, a more sophisticated way to combine the egg membrane with the solution could also solve possible problems with determining whether the part of the egg is positive or not.

    This lab was done to demonstrate which parts of a cell contained which macromolecule based on how different parts of the egg contained different macromolecules. From this lab, I learned that egg membranes have lipids and proteins; the egg yolk had monosaccharides, proteins, and a lot of lipids; and the egg white had a lot of proteins and some lipids. This helps me understand the concept of where each macromolecule in a cell is. Based on my experience from this lab, I can conclude that lipids and proteins make up the cell membrane, as well as some carbohydrates, such that cells can recognize each other. I can also conclude that the insides of a cell contains monosaccharides, proteins, and a lot of lipids. This could be applied to when it is required to know which parts of a cell contain which macromolecule.

Egg Monosaccharide Test
Photo Credits to Michelle Vu

Left to Right: Egg Membrane, Egg yolk, Egg White
Photo Credits to Ella Foster

Egg Polysaccharide Test
Photo Credits to Ella Foster