Video narration
How does carbon dioxide become sugar material-like water in a reusable bottle, with some taken out while the system refills itself? In the chloroplast's stroma, CO2 attaches to RuBP, the cycle's starting molecule, forming 3-PGA, its three-carbon product-not three steps. ATP and NADPH from the light-dependent reactions turn 3-PGA into G3P. One pass does not make glucose: one G3P leaves, while the rest rebuilds RuBP. That's how the C3 cycle fixes carbon and keeps accepting more.