Abstract
In the present review, the importance of analyzing full progress curves in enzyme assays is discussed. The atypical kinetic behavior that can be potentially displayed by enzymes in the performance of an activity assay, as well as the models explaining such behavior, are analyzed. These complex time-dependent kinetic patterns include hysteresis, damped oscillatory hysteresis, unstable product, and kinetic competence. The atypical time-dependent patterns are discussed with both real examples and In Silico simulations. When possible, the physiological implications of such kinetic behaviors are included. The importance of analyzing the derivative of the reaction rate of such atypical transitions as a method to distinguish them from the conventional non-atypical time progress curve is stressed.