CHEMICAL NATURE OF THE OXYGEN-TRANSFERRING FERMENT OF RESPIRATION IN PLANTS

Abstract

The effect of CO on the respiration of stamens of plums, stamens and pistils of daffodils, Spanish moss, green pine needles, and green leaves of tobacco, plum and oleander plants was examined by the Warburg technic and apparatus. The oxygen-transferring ferment of respiration in plants is a compound of a heavy metal, for in all these plant cells CO produces a strong reversible inhibition of respiration, and instead of the respiratory metabolism a non-oxi-dative splitting metabolism appears. The oxygen-transferring ferment in plants is a compound of iron: for, the ferment-CO compound dissociates in light; the CO inhibition of respiration ceases if the cells are illuminated and respiration again takes the place of the non-oxidatjve splitting metabolism. The sensitivity of the respiration ferment toward CO and the absorption of light by the respiration ferment-CO compound are of the same magnitude in the cells of the higher plants as in animal cells and aerobic bacteria. All these findings indicate that the oxygen-transferring ferment of respiration in plant cells is identical with the oxygen-transferring ferment phaeo-haemin.