chlorophyll

Chlorophyll breaks down in autumn leaves, unmasking yellow and orange carotenoid pigments that were present all along. Meanwhile, trees synthesize new red and purple anthocyanins, while shorter days and cooler nights trigger senescence—a programmed shutdown that eventually leads the tree to seal off and drop each leaf at a specialized abscission layer. This cascade of biochemical events helps trees conserve resources for winter.

How photosynthesis works at the molecular level — the light reactions, Z-scheme, electron transport chain, Calvin cycle, and why quantum coherence may be involved.

What would actually happen if humans could photosynthesize like plants? The math is brutal: you'd need skin the area of a small room, you'd still need food, and you'd have to spend most of your life lying flat in direct sunlight.

Photosynthesis takes sunlight, water, and CO₂ and produces sugar and oxygen. It powers nearly every food chain on Earth — and it produced the air you're breathing right now.