This investigation was designed for AP biology though it could be modified to work with students in introductory biology classes. First students learn the four macromolecules important to life: carbohydrates, lipids, proteins, and nucleic acids. They can then venture into the lab where they use indicators to test for the presence of these molecules in a Happy Meal. This will require you to buy a happy meal and place all of the contents into a blender to make “McMush.”
Each student or group receives a sample of the McMush and then use Benedict’s reagant to test for the presence of glucose, Sudan III to test for the presence of lipids, and Biuret’s Reagant to test for the presence of proteins. Positive reactions are observed in known solutions (glucose, starch, egg whites) and compared to negative reactions observed with water.
A prelab section summarizes the composition of the macromolecules emphasizing how each is composed of subunits called monomers. Students should read this section and fill out the charts prior to running the tests. A final analysis section uses the CER model (claim, evidence, reasoning) for students to communicate which macromolecules are found in the McMush and defend their answer with evidence and scientific reasoning.
This lab is a big hit for AP students!