where EA (J mol -1 ) is the apparent activation energy, R (J mol -1 K -1 ) is the gas constant, T (K) is the temperature, and A is the pre-exponential factor. In Arrhenius analyses, it is common to assume that there is no temperature dependence on A or EA, which may or may not be true. For example, temperature-dependant changes to EA (i.e., slopes in Arrhenius plots that are not single valued over the temperature range studied) are observed in some biological enzyme catalysis processes related to various biophysical transitions that affect the reaction thermodynamics. Therefore, evaluation of EAB activation energies by this approach is best conducted in a narrow temperature range, consisting of typical values at which the organism optimally operates. Equation 2 can be rewritten as follows: