fotoautotrofy

Fotoautotrofy (photoautotrophs) are organisms that use light energy to convert inorganic carbon, typically carbon dioxide, into organic matter. They rely on phototrophy for energy and autotrophy for carbon, distinguishing them from heterotrophs and chemoautotrophs.

The most common form is oxygenic photosynthesis, performed by plants, algae, and cyanobacteria, which splits water to release oxygen. Some bacteria perform anoxygenic photosynthesis, using reduced sulfur compounds or organic molecules as electron donors and producing sulfur compounds instead of oxygen.

Photosynthetic pigments such as chlorophylls and bacteriochlorophylls capture light energy to drive electron transport chains that generate ATP and NADPH. These energy carriers fuel carbon fixation cycles, most notably the Calvin-Benson cycle in plants and cyanobacteria, while some bacteria use alternative routes.

Major groups include land plants, green and brown algae, diatoms, and cyanobacteria, along with certain photoautotrophic bacteria. Ecologically, they are primary producers, forming the base of many food webs and contributing to global carbon and oxygen cycles. Evolutionarily, photoautotrophy arose early in Earth’s history, with cyanobacteria driving the Great Oxygenation Event and enabling aerobic metabolism.