An electron donor is a compound that gives up or donates an electron during cellular respiration, resulting in the release of energy. Microorganisms, such as bacteria, obtain energy to grow by transferring electrons from an electron donor to an electron acceptor. The microorganism through its cellular machinery collects the energy for its use. The final result is the electron is donated to an electron acceptor. During this process (electron transport chain) the electron donor is oxidized and the electron acceptor is reduced. Petroleum hydrocarbons, less chlorinated solvents like vinyl chloride, soil organic matter, and reduced inorganic compounds are all compounds that can act as electron donors. These reactions are of interest not only because they allow organisms to obtain energy, but also because they are involved in the natural biodegradation of organic contaminants. When clean-up professionals use monitored natural attenuation to clean up contaminated sites, biodegradation is one of the major contributing processes. Cellular respiration is the process in which the chemical bonds of energy-rich molecules such as glucose are converted into energy usable for life processes. ... A microorganism or microbe is an organism that is so small that it is microscopic (invisible to the naked eye). ... Kingdoms/Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular: bacterium) are a major group of living organisms. ... An electron acceptor is a compound that receives or accepts an electron during cellular respiration. ... The electron transfer chain (also called the electron transport chain, or simply electron transport), is a series of protein complexers and lipid messengers spanning the inner mitochondrial membrane that accepts electrons from electron donors such as NADH or succinate, shuttles these electrons from within the mitochondrial matrix across the inner... In chemistry, a hydrocarbon is a cleaning solution consisting only of carbon (C) and hydrogen (H). ... Vinyl chloride, also known as chloroethene in IUPAC nomenclature, is an important industrial chemical chiefly used to produce its polymer, polyvinyl chloride (PVC). ... Biodegradation is the decomposition of organic material by microorganisms. ...