Carbon Dioxide & the Hill Reaction

Abstract

Pea chloroplasts incubated for 2-3 hours under a CO2-free atmosphere may lose the greater part of their Hill reaction capacity if small anions such as formate, acetate, or chloride are present. This effect of CO2 removal is completely reversible, even after the chloroplasts have been illuminated. Ferricyanide reduction is much more dependent on the presence of CO2 than is flavin reduction. The reaction which is directly inhibited by CO2 removal seems to be neither a photochemical reaction nor a reaction which is directly coupled to phosphorylation.