Metabolism Autotrophs such as plants can construct the complex organic molecules in cells such as polysaccharides and proteins from simple molecules like carbon dioxide and water. Heterotrophs, on the other hand, require a source of more complex substances, such as monosaccharides and amino acids, to produce these complex molecules. Organisms can be further classified by ultimate source of their energy: photoautotrophs and photoheterotrophs obtain energy from light, whereas chemoautotrophs and chemoheterotrophs obtain energy from inorganic oxidation reactions. Photosynthesis is the synthesis of carbohydrates from sunlight and carbon dioxide (CO). In plants, cyanobacteria and algae, oxygenic photosynthesis splits water, with oxygen produced
Electrochemical reduction of carbon dioxide Electrochemical reduction of carbon dioxide The electrochemical reduction of carbon dioxide (ERC) is the conversion of carbon dioxide to more reduced chemical species using electrical energy. The first examples of electrochemical reduction of carbon dioxide are from the 19th century, when carbon dioxide was reduced to carbon monoxide using a zinc cathode. Research in this field intensified in the 1980s following the oil embargoes of the 1970s. Electrochemical reduction of carbon dioxide represents a possible means of producing chemicals or fuels, converting carbon dioxide () to organic feedstocks such as formic acid (HCOOH), methanol (CHOH), ethylene (CH), methane (CH), and