Woodside Biology

#ModBio Workshop Day 11



  1. WB Discussion Cellular Respiration Laboratory
  2. Simulating Cellular Respiration with MolyMods
  3. Exercise 2 – WB & Discuss
  4. What Do Plants Eat?
  5. Simulating Photosynthesis with MolyMods
  6. Do Plants Photosynthesize all the Time?

The whiteboard discussion of our Cellular Respiration Laboratory was fairly straight forward.  I really struggled with this laboratory because I really wasn’t sure my students were confused about where the CO2 comes from.  But than again, I guess I never really asked them.  Eventually we agreed that the living yeast exposed to the air generated more CO2 than the living yeast under the mineral oil.  This might be a good time to then discuss generally how aerobic cellular respiration is more efficient that anaerobic cellular respiration.
Next we Simulated the process of Cellular Respiration with MolyMods.  I really like the MolyMods.  I’ve used the rubber tube bonding type before.  My students sometimes struggle with the 3-D representations of this type.  The MolyMods use a space-filling model instead of a stick-model.  I think this would make more sense to my kids because they have not taken a chemistry course yet.  We started with a glucose molecule and 6 O2 molecules.  We were directed to breakdown the glucose model and build the products of cellular respiration.  We discussed how we measured CO2 production so that was one product, then Angela used the breathing on a mirror analogy to get at water vapor.  Bring from Maine, I’d use the seeing your breathe in the winter route myself.  After building the CO2 and H2O molecules, we created a balanced equation.  We then researched the organelle where cellular respiration take place, drew a labeled diagram and whiteboarded.  This activity would be followed by some direct instruction on the details of cellular respiration as necessary for our own courses.

The model development phase began with an exercise.  In this exercise we created several different representations for the process of cellular respiration.  I really like that the kids would need to provide an equation, a verbal, a graphical, and an energy LOL chart representation for both aerobic and anaerobic cellular respiration.  Next we drew pictorial representations for several levels of complexity; multicellular organism, cellular, molecular.  Yet another multi-prong approach.  Next was a simple compare and contrast for aerobic and anaerobic.  We finished with a storyboard portion for two different environmental conditions; no oxygen and lots of oxygen.  We whiteboarded a selection of answers and discussed.

Next we used the MolyMods again to simulate photosynthesis.  We already had the CO2 and H2O built from the previous simulation of cellular respiration.  We briefly discussed what plants need to make sugar and were on our way.  I think it is cool that the MolyMod bags will be all set up for next year with the glucose and O2 built.  This lead to the question of “Do plants make their food all the time?”.

To answer that question we used the CO2 and O2 probes and spinach leaves in light and dark environments.  I really like the BioChamber 2000.  At my school we’ve used the BioChamber 250, and I don’t find that we get very consistant data because you can only fit a few leaves in 250-mL chamber.  We were able to create a single layer of many leaves in the 2000-mL chamber.  We also used a circular fluorescent light that wrapped around the entire chamber rather than one single light shining down.  Our homework for the evening was to create a visual, diagrammatic  and graphical representation of our results that we will be whiteboarding tomorrow morning.