THEORY OF OSCILLATIONS IN PEROXIDASE CATALYZED OXIDATION REACTIONS IN OPEN SYSTEM

1. The applicability of the (1910) Lotka6 model to the horseradish peroxidase (donor: H2O2 oxidoreductase, EC 1.11.1.7) catalyzed oxidation reactions in an open system is investigated. 2. The input of reactant by diffusion in stead of a constant input flux does not prevent oscillations of low damping. The gain of 3 in the branched chain reaction in the peroxidase system in stead of 2 in the Lotka model causes an increased damping, but the low damping observed in the experiments is still possible. 3. The combination of linear branching and quadratic termination, which is commonly believed to prevail in the peroxidase system, leads to a damping which is much higher than observed in the experiments. 4. A critical lower concentration of donor is known to exist below which the peroxidase catalyzed oxidation does not take place. This phenomenon is predicted by models of the Lotka type where the branching and the termination are both linear or both quadratic. It does not occur if the branching is linear and the termination is quadratic. 5. Compound III is not assumed to play any significant role in relation to the origin of the damped oscillation. © 1969.