Photosynthesis

Photosynthesis is the biochemical process by which plants, algae, and certain bacteria convert sunlight into chemical energy, storing it in glucose and other organic molecules. This process is fundamental to nearly all life on Earth: it produces the oxygen we breathe and forms the base of most food chains.

The mechanism occurs primarily in chloroplasts through two stages. The light-dependent reactions occur in the thylakoid membranes, where photons excite electrons in chlorophyll, driving the splitting of water and generating ATP and NADPH. The light-independent reactions (or Calvin cycle) use these energy carriers to fix carbon dioxide into glucose in the stroma.

Different plant types have evolved variations: C3, C4, and CAM pathways represent adaptive strategies for different climates and environments.

Understanding photosynthesis matters for agriculture, climate science, and renewable energy research—including artificial attempts to replicate the process through artificial photosynthesis.

Related

Chlorophyll, Respiration (biology), Carbon cycle, Seed germination, Plant breeding