Photosynthesis in Ecosystems

Key points:

• Energy enters an ecosystem when light energy from the sun is transformed into chemical energy. This happens during photosynthesis.

• Photosynthesis is carried out by photosynthetic organisms.

• Photosynthesis drives the movement of matter, or atoms, between organisms and the environment.

  • Photosynthetic organisms take in and use carbon dioxide and water from the air and soil.

  • Photosynthetic organisms release oxygen into the air. Organisms throughout the ecosystem use this oxygen to breathe.

  • Photosynthetic organisms produce sugars, which become part of the organism’s biomass. When the photosynthetic organism is eaten, its biomass provides matter and energy to the organism that eats it.