Labs / Biology
Cellular Respiration
Drag across the cell to drop in glucose, then set the feed rate and decide whether oxygen is available. Green sugars split in glycolysis, pyruvate feeds the Krebs cycle, and amber electron carriers (NADH & FADH₂) shuttle to the membrane where a proton gradient spins ATP synthase. Switch off oxygen and the whole engine falls back to fermentation.
ATP/glucose ≈ 38CO₂ 0O₂ used 0
What to try
- With oxygen on, how many ATP does the cell squeeze out of one glucose? Where do almost all of them come from?
- Flip oxygen off. Why does the ATP-per-glucose readout crash from ~38 to just 2, and why do CO₂ and O₂ stop entirely?
- Watch the carriers. What actually makes ATP synthase spin faster — more glucose, or the proton gradient it builds?
- Crank the feed rate to maximum in fermentation. Can a sprinting muscle keep up with its energy demand this way, and for how long?
- If glycolysis alone still yields 2 ATP without oxygen, why did life bother evolving the whole Krebs-cycle-and-membrane machinery?