A leaf builds with carbon from the air.: sources & model

Open a leaf, explore a chloroplast, and supply a tiny carbon-building recipe. Discover what comes from air, what comes from water, and what light contributes.

What supports the explanation?

What this model assumes

1. Finite stoichiometric recipe and qualitative chloroplast context. No crop-yield, gas-exchange, photosynthesis-rate, drought or climate model.
2. Molecules are symbols at exaggerated scale. The chloroplast is an original structural teaching model, not microscopy.
3. The water-to-O₂ arrow identifies oxygen origin. It does not show a complete atom-resolved light-reaction pathway or fixed photons-per-ATP ratio.
4. A finite recipe, not a growing plant: For one net G3P accounting batch, supply 3 CO₂, 9 ATP and 6 NADPH. The existing three-RuBP pool contains 15 carbons. Adding three carbons gives 18; exporting a three-carbon product leaves 15 to regenerate the pool.
5. Energy and matter are different: Turning off light in the context view stops its replenishment cue. The recipe bench has separately supplied carrier stocks, which remain available without light. Light is not converted into carbon atoms, and existing products do not disappear in darkness.
6. Dependencies are not rates: Without CO₂ there is no new carbon export; without sufficient carriers a complete batch cannot finish. The six-second animation is an explanation sequence, not a reaction time or a prediction of plant growth. Plants also respire.

What has been checked

Analytical reference cases, conservation or transition invariants, finite drawing commands, bounded setup parsing, discovery and route integrity are checked automatically. These checks do not establish anatomical fidelity, learner outcomes or browser/device compatibility. Independent subject review, learner trials, comprehensive accessibility review and browser video encoding checks remain pending.

Each source supports the associated claim. Sources do not certify this implementation or its visuals.

About the cover illustration

The topic card uses an AI-generated editorial illustration. It introduces the subject; it is not a validated anatomical reference or a measured landscape. The experiment’s diagrams, readouts and assumptions explain the model separately.