Egg Macromolecules Lab

      In the egg macromolecules lab, we asked if monosacchardies are present in the cell nucleus, represented by the egg yolk. We found that they indeed were present in the egg yolk, as a chemical test involving benedicts solution produced a color change from blue to green (rated a 7/10 on our scale compared to the 0/10 of water). This indicated the presence of monosaccharides, in this case glucose, present in the cell nucleus to provide energy, and supports our claim by showing how they can be found in the egg yolk in our experiment.

Monosaccharide test results
(control, egg white, egg yolk, egg membrane from left to right)

      Furthermore, we also asked if proteins can be found in the egg white, representing the cytoplasm. Here, we found that they were present, and the CuSO4 compound we introduced produced a color change from dark blue to light purple. This was a 9/l0 on our scale, and was supported by the presence of enzymes and structural proteins throughout the cytoplasm. Thus, this supports the claim with proteins.

Protein test results
(control, egg white, egg yolk, egg membrane from left to right)

      In addition, we asked whether lipids are present in the egg membrane. We found that lipids are in the cell membrane, as the Sudan III test yielded positive results of a color change from red to brownish orange (7/10). This supports the claim and can be explained by the presence of lipids as phospholipids making up the cell membrane.

Some macromolecule data tables

      While our hypothesis was supported by our data, several errors may have occured and thus skewed the results. For example, we may not have added the correct amount of test substance for each macromolecule test. This potentially incorrect drop amount may have caused the color and scale rating to be lower than the actual amount, due to having less test substance to create a noticeable effect; more care on correct dropper measurement would prevent this. Furthermore, the amount of test sample could have changed our results as well, and made the data lower due to a more diluted exposure to the testing substance. Standardizing this in some way could improve and negate this error; for example, setting a specific measure for each part of the egg, such as a mass measure, could make it more even across tests. These errors may have affected several of the tests, as every group member used a different (estimated) amount of egg membrane, yolk, or white to test.

      Lastly, this lab was done in order to identify macromolecules in different parts of the cell. This taught me the concept of macromolecules being the building blocks behind many of the cell parts and organelles. I learned how glucose can be found in the cell nucleus, how lipids make up the cell membrane as phospholipids, and how structural proteins are found throughout the cell, including in organelles. All in all, based on my experience from this lab, I would also be able to identify the presence of various macromolecules in different types of cells, regardless of their type or origin, even without much knowledge of the cell itself.