eindacceptor

An eindacceptor, also known as a terminal electron acceptor, is a chemical species that accepts electrons at the end of an electron transport chain or redox process. It functions as the oxidizing agent that allows continued electron flow and energy capture in the system. In cellular respiration, the terminal electron acceptor is typically an inorganic molecule with a suitable redox potential. In aerobic respiration, molecular oxygen serves as the final acceptor, being reduced to water. In anaerobic respiration, alternative electron acceptors such as nitrate, nitrite, sulfate, carbonate, or ferric iron can be used, yielding different energy efficiencies and metabolic products. In photosynthesis, the final electron acceptor in the light reactions is usually the electron carrier NADP+, which is reduced to NADPH and used in carbon fixation.

In chemistry and biochemistry more generally, an electron acceptor is any species that undergoes reduction by accepting electrons from an electron donor. The feasibility and extent of electron transfer depend on the redox potentials of the donor and acceptor; reactions proceed spontaneously when the acceptor has a higher affinity for electrons (a more positive redox potential) than the donor. The term is used across disciplines, including microbiology, biochemistry, and environmental science, and is important for understanding energy yields, respiration strategies, and biogeochemical cycles.

Common examples include O2, NO3-, MnO4-, Fe3+, SO4^2-, and CO2 under certain microbial metabolisms.