All organisms use oxidation-reduction reactions to harness energy, and this newly harvested energy is used to produce ATP. Oxidation is defined as the loss of electrons. Reduction is the gain of electrons. The energy in fuel molecules (often carbohydrates) is in the form of electrons. When electrons are removed from their high-energy state in fuel molecules (the electron donors), those molecules are oxidized. The electrons must be added to another molecule, which serves as the electron acceptor. As it gains electrons, the electron acceptor is reduced. When these electrons arrive at the final electron acceptor, they are at a lower-energy state compared to their original position in the electron donor. The goal is to harness the energy the electrons lose during this transfer process. In this activity, you will examine three equations and indicate which reactants are electron donors and which are receptors. In addition, you will identify the oxidized product and the reduced product.