Modeling Enzyme Activity with Pool Noodles

Enzymes and how they function is such vital concept to understand for AP Biology, but it can be challenging to understand something that you can't actually see.  Last year was the first time we worked with pool noodles trying to demonstrate how enzymes work. Here's the blog post about it. I thought it went well and decided to do it again this year. Since last year, I have discovered Expo neon window markers.  This year, instead of labeling our pool noodle enzymes on white boards, students just wrote right on their lab tables. It looked fabulous!

Book-ending Christmas break with Lorenzo's Oil

Keeping students engaged on the last day before Christmas break can be a challenge, but I don't believe in wasting time.  We just finished our unit on Mendelian Genetics, and watching Lorenzo's Oil is a great complement to what we've done in AP Biology so far.  Last year I found a study unit on the movie here. We started with the activity demonstrating what happens to nerve signals as they become demyelinated. Students start with a "brain bucket full of signals (ping pong balls) and must pass them from one student to the next until it reaches the "body" bucket. We count how many signals (ping pong balls) make it into the body bucket in 10 seconds and then start again. But the second time
we do it, two students have to sit out and the remaining students may not move any closer to each other. We repeat one more time with two more students sitting out, to get a feel for how signal transmissions changes as more of the myelin is lost from nerve cells.

Then we get out the snacks and start watching the movie.  There are questions provided in the study unit to help them keep focused and delve deeper into the science of the movie.

When we get back from break we do the competitive inhibition activity with paper clips and finish the movie.  In the competitive inhibition activity we look at how providing more unsaturated fatty acids "competes" with the saturated fatty acids to hinder the production of very long chain saturated fatty acids (VLCSFA).

As we finish the movie, it leads naturally into a discussion of medical ethics, and is a great segue into our molecular genetics unit.

Working with Enzyme Models

I love to have models that students can work with to help understand a concept. So much of what we do in AP Bio is too small to see--even with a microscope.  We can talk about how these small things work, but I find it more meaningful if we can get our hands on it. We do complete the AP enzyme lab and get to experiment with what factors affect the rate of the enzyme catalyzed reaction of peroxidase with hydrogen peroxide and guaiacol.  Fortunately, before the lab we did two activities to give them some concrete pictures of what is happening with enzymes.

The first exercise we did involved using pool noodles as models of enzymes, substrate, and inhibitors (both competitive and allosteric).  I got this idea from a blog post on We Teach High School and got the directions from Mr. Mohn's blog (Toucan Play That Game). Students use pool noodles to demonstrate what is happening in 4 different scenarios.  Here is the document I put together for my students to use from those two blogs.

I loved this activity.  "Allosteric" sounds so esoteric, but when you can push a wedge of a pool noodle into another pool noodle and watch the active site change, it suddenly becomes real.

I found the Need For Speed lab on Pinterest.  I modified it to use in my classroom.  After doing the activity this week, I've decided that I want to modify it even more.  Since the students had already worked with competitive inhibitors with pool noodles, I think we can skip that part with the pennies and instead focus on changes in the rate of reaction when enzyme and substrate concentrations change.