Standard reduction potential (E o ): The E o of various redox pairs can be ordered from the most negative E o to the most positive. The more negative the E o of a redox pair, the greater the tendency of the reductant member of that pair to lose electrons. The more posi- tive the E o , the greater the tendency of the oxidant member of that pair to accept electrons. Therefore, electrons flow from the pair with the more negative E o to that with the more positive E o . The E o values for some members of the electron transport chain are shown in Figure 6.12. [Note: The components of the electron trans- port chain are arranged in order of increasingly positive E 0 values.]