Macromolecules: My Obsession with Paper Models

If a stranger were to walk into my room, the first thing they would notice is all the bright colored paper models hanging around my room. These models were made by my students and, I hope, help them learn some of the basics of macromolecules. The Nebraska state standards say that students should be able to identify carbohydrates, lipids, proteins and nucleic acids. I'm not sure what they mean by identify, but I assume a student should recognize one of these molecules if they see a picture of them, recognize them from a description, and recognize them from their functions. To help students master all three of these skills we have to do more than just give them notes to stare at. Students learn all sorts of different ways, so activities that stimulate more than one of the senses are always good. I do think it is important for students to be able to take good notes because, regardless of how well they learn a concept from notes, if they want to be successful taking college science classes they need to practice taking notes. However, just sitting and writing is ineffective for many high school students. Therefore, each class makes a paper model of each macromolecule.
Carbohydrates
The first complex molecule we discuss is carbohydrates. As they are designing these models, I overhear lots of interesting comments. Students will ask why are they all hexagons and another student will remind them that the monomer is glucose or a student will ask why theirs looks different than another class' model and a student will explain that one each one represents a different carbohydrate. This seems like a great way for students to reflect on what they learned about each macromolecule rather than just stare at a piece of paper. Also, when I review these concepts, I can just walk around the room and point to a model and ask them what it is, how they know that, and what its function is. Instead of them trying to recall what they memorized from their notes, they are recalling the steps they took while building the model and the conversations they had.

Starch

Cellulose

Glycogen

Protein

The next model we made was a protein model. We only talked about proteins in general, but we did discuss primary, secondary, and tertiary structure.We discussed that proteins are a chain of amino acids and then we built that primary structure. Then we discussed secondary structure and the students had to figure out how to give the chain alpha coils and beta sheets (lots of scotch tape!). Then they folded it into the 3-d shape of their choice. Now instead of memorizing what each of these structures are they can just think back to what was the first thing we did, the second thing, and the last thing. I also tweeted pictures of each of the structures so if they couldn't remember, they could just look back at that tweet. Studying tweets of things you did is better than studying a piece of paper.

Tertiary structure of a protein

Lipids

Saturated lipid
Straight chains

Polyunsaturated lipid
Chains with many bends

Monounsaturated lipid
Chains with one bend

Nucleic Acid

ATP/ADP
(with detachable Phosophate)

DNA

RNA

I believe anything that gets students moving, touching, doing and discussing will help them learn more than just sitting and writing. They also really enjoy getting to hang their models anywhere they want in my room and if making and hanging models makes science more enjoyable for sophomores, I am all for it. I posted pictures of these models on my twitter account as they were making them so feel free to check those out as well.

@brandon_timm or #ahsbio