Instructor
Dr. Hollister
Projected prompt as students arrive: "A marathon runner eats an apple at mile 20. Ninety minutes later, how many of the carbon atoms from that apple are still in her body — and where did the rest go?"
Annotated sketch of the mitochondrion on the board. Students complete guided notes as each stage is unpacked. Emphasize that cellular respiration is controlled combustion — the same chemistry as fire, staged across dozens of enzymes.
Cytoplasm. Glucose (6C) splits into two pyruvate (3C). Substrate-level phosphorylation. Anaerobic — the oldest pathway.
Mitochondrial matrix. Acetyl-CoA fed in; carbon exits as CO₂. Electron carriers loaded for the main event.
Inner membrane. ETC pumps H⁺; chemiosmosis drives ATP synthase. O₂ is the final electron acceptor — hence aerobic.
Teams compare CO₂ production in germinating versus dormant seeds at two temperatures. Goal: produce a defensible rate (ppm CO₂ per minute per gram) and explain any deviation from predictions.
| Condition | Rate | σ |
|---|---|---|
| Germ. 25 °C | 1.80 | 0.22 |
| Germ. 10 °C | 0.64 | 0.14 |
| Dormant 25 °C | 0.08 | 0.04 |
| Glass beads | 0.01 | 0.01 |
Units: ppm CO₂ · min⁻¹ · g⁻¹. Use to triangulate group findings.
Each group posts one claim linking their temperature result to enzyme kinetics, supported by a specific data point. Class evaluates whether the evidence actually supports the claim, or merely correlates. Return to the morning's apple prompt — students revise predictions in blue ink.
Formal CER write-up with graphed data, error analysis, and a paragraph connecting observed CO₂ rates to Q₁₀ and enzyme theory.
Scored for accuracy on the cyanide question; student-generated questions drive Wednesday's opening review.
Circulating rubric notes probe-handling technique, group discourse quality, and willingness to revise initial predictions.