molecular_function electron carrier activity 2Fe-2S electron transfer carrier 3Fe-4S/4Fe-4S electron transfer carrier Any molecular entity that serves as an electron acceptor and electron donor in an electron transport chain. An electron transport chain is a process in which a series of electron carriers operate together to transfer electrons from donors to any of several different terminal electron acceptors to generate a transmembrane electrochemical gradient. GO:0009053 GO:0009054 GO:0009055 Reactome:REACT_100606 Reactome:REACT_107372 Reactome:REACT_107740 Reactome:REACT_107845 Reactome:REACT_108215 Reactome:REACT_109222 Reactome:REACT_28440 Reactome:REACT_29712 Reactome:REACT_31774 Reactome:REACT_6154 Reactome:REACT_78399 Reactome:REACT_81671 Reactome:REACT_89868 Reactome:REACT_94498 Reactome:REACT_98413 Reactome:REACT_98930 Reactome:REACT_99683 Reactome:REACT_99848 adrenodoxin-type ferredoxin amicyanin azurin bacterial-type ferredoxin chloroplast-type ferredoxin copper electron carrier dicluster bacterial-type ferredoxin electron acceptor activity electron carrier, chlorophyll electron transport system electron donor activity electron transfer flavoprotein electron transfer flavoprotein, group I electron transfer flavoprotein, group II electron transporter activity high-potential iron-sulfur carrier iron-sulfur electron transfer carrier molecular_function monocluster bacterial-type ferredoxin mononuclear iron electron carrier polyferredoxin redox-active disulfide bond electron carrier rubredoxin small blue copper electron carrier thioredoxin-like 2Fe-2S ferredoxin