In this project in the Physical Chemistry Program of the Chemistry Division, Alexander Scheeline of the Department of Chemistry of the University of Illinois, Urbana will study the horseradish peroxidase oscillator using a reducing agent, oxygen as the oxidant, and cofactors such as methylene blue and 2,4-dichlorophenol. Recent work has led to semiquantitative understanding of this system. In the new research proposal new experiments will be conducted to elucidate fully the mechanism of this oscillating reaction and to be able to search for other biologically interesting chemical oscillators. Biochemical oscillators such as those studied in this project are of interest to unravel the mechanism of biological clocks, which are at the basis of important cellular transmission processes, although in that case also a membrane is involved.