The primary process through which energy is transferred in food webs is photosynthesis. In this process, producers (typically plants, algae, and some bacteria) convert sunlight into chemical energy by synthesizing glucose from carbon dioxide and water. This stored energy is then transferred through the food web as organisms consume one another, from primary consumers to higher trophic levels. The efficiency of energy transfer is critical to ecosystem functioning, informing studies of ecology and sustainability as trophic interactions shape the health of environments.