MarsnutBack to Home ↗

For the curious at heart. A pocket-sized collection of science-inspired games.
Made for a quick break, a little discovery, and one more round.

DESKTOP / TABLET / MOBILE
Your browser is your playground.

HOW TO PLAY

Defend the chemistry

Survive a 120-second round with at least 55% integrity and preserve the cytosolic peroxide signal in at least 60% of the two signaling windows (0–25 and 105–120 seconds).

  1. Select a compartment. Tap its cell region or a compartment button. The right panel shows its ROS loads.
  2. Build an enzyme. SOD costs 2 credits; GPx and catalase cost 3. Click again to cycle low → high → paused → low. Catalase is restricted to peroxisomes in this model.
  3. Follow the reaction. SOD: 2 O₂•⁻ + 2 H⁺ → H₂O₂ + O₂. Pair it with GPx to clear the resulting peroxide.
  4. Maintain glutathione. GPx: H₂O₂ + 2 GSH → 2 H₂O + GSSG. Recycling: GSSG + NADPH + H⁺ → 2 GSH + NADP⁺. Switch metabolism toward NADPH if reducing power falls.
  5. Adapt to the bursts. Mitochondrial leak begins at 25 s, peroxisomal burst at 55 s, double pressure at 85 s, recovery at 105 s. Catalase: 2 H₂O₂ → 2 H₂O + O₂.
  6. Preserve signaling. Excess clearance can suppress the signal. Pause unnecessary enzymes during recovery. The teal band is a game target, not a universal physiological range.

Controls: tap/click, 1–3 select, Q/W/E enzymes, R metabolism, G recycling, P pause. Help and hidden tabs pause the simulation. Untimed practice repeats the same five phases.

Biology and model limits

H₂O₂ participates in redox signaling; superoxide and peroxide have different chemistry. This mammalian-cell model omits peroxiredoxins, thioredoxin, hydroxyl radical chemistry and repair pathways. It shares a glutathione/NADPH budget across compartments and simplifies peroxide exchange. Protein shapes are illustrative.

Sources: Bae et al. (1997), H₂O₂ and EGF signaling; RCSB PDB, human catalase; RCSB, superoxide dismutase.