Many metabolic reactions proceed simply through the transfer of electrons. In these reactions, the transfer of electrons is always coupled: one component of the reaction loses electrons (electron source) and another component gains these electrons (electron sink). These coupled reactions are known as redox reactions.
When something is oxidized, it _____ electrons and when somethins is reduced, it _____ electrons.
A. gains; loses
B. loses; gains
C. gains; gains
D. loses; loses