In ecology, producers are referred to as autotrophic organisms that obtain energy-rich biomass from inorganic compounds ( primary production ). In addition to the green plants, which operate primary production through photosynthesis , there are organisms that use chemical reactions as an energy source ( chemotrophy or chemosynthesis ).
The photoautotrophic primary producers are mostly plants . Through photosynthesis , they produce sugars from water and carbon dioxide using light energy . They use part of the sugar in cell respiration as an energy source for further building metabolism . They use another part of the sugar as a raw material for the synthesis of more complex components of biomass , i.e. mainly proteins , fats and nucleotides ( ATP , DNA ). To do this, they absorb other chemical compounds such as phosphate , nitrate and sulfate in order to incorporate nitrogen , phosphorus , sulfur, etc. into the biomass.
In stagnant waters, the role of primary producers is preferred by the algae of the plankton . These also include photosynthetically active prokaryotes , in particular cyanobacteria (alias blue-green bacteria, formerly called blue-green algae); in special biotopes, however, other bacteria or archaea capable of a more primitive form of photosynthesis also occur as primary producers .
For example in the deep sea or in locations with little light but with high-energy inorganic compounds there are also producers who can produce biomass with the help of chemical energy through chemosynthesis .