Macromolecules the "Legos" of life

The most challenging of all chapters in biology I think for sophomore level high school students is the one on the biochemistry of life. I try all types of techniques to help them with this subject matter. One thing is to use the molecule building kits to make the material presented on the 2-dimensional textbook page become a 3-dimensional reality. I remind them that they are made up of millions if not billions of these molecules and they are not flat structures themselves. Yesterday we built functional groups: hydroxyl, carbonyl, carboxyl, and amine. Then I had them put some of them together to build the simplest of all amino acids - alanine as pictured below. One of the biggest challenges is to convince them it is time to stop playing and clean up. Don't leave any atoms or bonds on the floor.