B. Portion of released energy that is used or has potential to be used for work is free energy. K. Enzymes are protein catalysts that increase reaction rates without themselves being changed. Also known as redox reaction. D. Electron tower 1. Oxidation-reduction reactions involve two redox pairs, one serving as electron donor, other as electron acceptor.
Reaction is two coupled half reactions.
The reduced molecule of a redox pair which has the more negative E 0 donates electrons to the oxidized molecule of the other pair. The greater the difference in redox potential between the redox pair serving as electron donor and redox pair serving as electron acceptor, the greater the energy available from the reaction. The same redox pairs may serve as either electron donors or acceptors, depending on which redox pair they are coupled with. E. Part of the energy liberated during exergonic oxidative portions of reactions are conserved in the bonds of reduced products, some energy is used for work, some energy is lost as heat. Electron carriers are compounds acting as relays in cell that transfer electrons from initial electron donor to final electron acceptor.