Dr. Raima Larter is supported by a grant from the Experimental Physical Chemistry Program to study the chemical kinetic origin of chaos in selected chemical reactions. The reactions to be studied are models of oscillatory reactions which occur in many biologically important processes such as oscillatory membrane potential in pacemaker cells in the heart and pancreas, organismic circadian rhythms of all types, and the cell-division cycle. Dr. Larter will study the origin of oscillatory behavior in the peroxidase enzyme catalyzed oxidation of nicotinamide adenine dinucleotide. The research focusses on four questions: 1) Are mixed-mode oscillations observed in simulations likely to be experimentally observable? 2) What is the mechanism by which chaos arises in this system, and does it involve the wrinkled torus? 3) What are generic chemical kinetic features giving rise to a devil's staircase in mixed-mode oscillations? and 4) What is a more realistic, experimentally based mechanism for the peroxidase reaction?
