Egg Macromolecules Lab

         In this lab, we asked the question, can macromolecules be identified in an egg cell? Looking at our results, we found that different parts of the egg have different macromolecules in them. The egg membrane tested positive for lipids. When the egg membrane solution was mixed with Sudan III, it produced an orange color, indicating that lipids were present in the egg membrane solution. Sudan III is an indicator that changes color to orange when a lipid is present in a solution. The egg white tested positive for proteins. When the egg white solution was mixed with a combination of copper sulfate (CuSO₄) and sodium hydroxide (NaOH), the solution turned into a purple color, showing that proteins were present in the egg white solution. The egg yolk tested positive for carbohydrates and more specifically, polysaccharides. When the egg yolk solution was mixed with iodine, it turned yellow-brown, showing that polysaccharides were in the egg yolk.

         Our data contradicts our initial hypothesis on what macromolecules are going to be in each part of the egg. For the egg yolk, we predicted that it will be mostly protein, but it tested for more polysaccharides than proteins. Also, for the egg white, we predicted that it will mostly be carbohydrates, but it tested for more proteins than monosaccharides and polysaccharides. While our hypothesis for the egg membrane having mostly lipids was supported by our data, there could have been errors due to contamination of pipets or not measuring the right amount of egg membrane or Sudan III. These errors would have affected this lab by giving results for other macromolecules and making our data false and inaccurate, or by causing the macromolecule to give wrong information when testing if the right amount of the substance is not used. Because of these potential errors, in future experiments I would recommend that the substances be measured correctly and as accurately as possible and try to keep things neat and organized while doing the experiment.

         This lab was done to demonstrate the roles and functions of macromolecules in eggs. From this lab I learned that membranes usually contain lipids, egg whites usually contain proteins and egg yolks usually contain polysaccharides which helps me understand the concept of each macromolecules' function and role in a cell. Based on my experience from this lab, I could apply this knowledge and skills to test different substances for macromolecules.