Studying Macromolecules

Last year, my students struggled to get their heads around the macromolecules chapter.  We did a lab that involved building several fairly large and complex ball and stick molecule models.  I found that it didn't help the information stick and when they saw the chemical structures on paper, it didn't look enough like the models to see the connection.  Since their tests are primarily on paper, I wanted them to be comfortable with those structural models.

This year I used the lab from Kim Foglia on the Explore Biology site and modified it just a bit.  It involved printing A LOT of pages.  I didn't want to have to print all of those pages every year, so I laminated all of the pages and modified the instructions. Instead of cutting parts of the molecules off as they went through the dehydration reaction, I had students fold the paper back.  Reusing them means peeling off all the tape, but at least I don't have to make all of those copies again.

Oops! I didn't realize that when I moved
the DNA molecule, several of the
 nitrogenous bases moved behind the paper.

 I revised the directions and gave them to my students in this Google doc. I also wanted a single sheet that would give them the key properties of the molecules at a glance, so I also had them working on completing this chart as they did the lab. We'll see in a week and a half when they take their first unit test how much this has helped their understanding.

Here are the files found on Explore Biology if you are having problems with the site.

Going Squirrel-ly

Two foraging patches in the "unsafe" location

My 6th grader is participating in a Science Fair in January.  Fortunately, she is as anti-procrastination as I am, so we have begun the experiment this week.  We decided on an experiment from projectsquirrel.org.  This way, the data she collects actually becomes part of a set of real information. We are finding though, that squirrels are not always willing participants, behaving the way we want them too. On the first day, they didn't forage the corn at all, then on the second day, they ripped the screw holding one of the cobs down and ran away with the cob.  On the third day, we had to go out for the morning, and when we got home, the squirrels had stolen away all four cobs.  Fortunately, we still had 6 hours of daylight, so we put out 4 more cobs and were able to get some data.

Most of the embryos were excised from these kernels. 

Of course, there were two more stealing attempts.  This time, the squirrel ran with not only the cob, but the small eye screw, wire, and 6 inch screw that anchored it in the ground.  I found it the first time--the cob had only gone about 20 feet from the foraging patch.  The second time we realized it was missing, my youngest daughter saw the squirrel trying to carry it up a pine tree.  The weight of the 6 inch screw dangling from the cob must have been too much though, since the squirrel eventually dropped it from the tree. The fourth day went much more smoothly.  We did our best to plant the screws firmly in the ground, and all of the cobs remained on the foraging patches where they belonged.  The squirrels obliged by eating most of the kernels off the cobs in the foraging locations that we had chosen as "safe".

Reading Guides for Unit 2--Cells

I finished tweaking the Holtzclaw's guided reading questions to fit within the new AP Biology curriculum framework for my Unit Two chapters.  These should work for both the Campbell Biology texts and Biology in Focus (although the chapter numbers will be a little different).  Chapter 6 focuses on organelles and their functions.  Chapter 7 focuses on membranes and transport into and out of cells.  This is where we do the AP diffusion and osmosis lab.  Chapter 11 introduces the signal transduction pathway.

Chapter 6

Chapter 7

Chapter 11

Happy reading!