PHOTOXIDATION OF ASCORBATE TO OXALATE AND THREONATE MEDIATED BY CHLOROPLASTS IN FAR RED LIGHT

Abstract
Abstract— Chloroplasts illuminated with light absorbed predominantly by Photosystem I can mediate the photoxidation of ascorbic acid to threonic and oxalic acids. Two micromoles of oxygen are consumed for each micromole of ascorbic acid added. The kinetics of this endogenous chloroplast system closely resemble the kinetics of an artificial flavin‐manganese‐catalase system in which flavin is the photosensitizing dye.