Oxygen Evolved by Isolated Chloroplasts

Abstract

THE high affinity for oxygen possessed by muscle hæmoglobin suggested its use as a very sensitive spectroscopic method for detecting and measuring small quantities of oxygen¹. This method has now been applied to study the oxygen evolution of isolated chloroplasts exposed to light. While being much less sensitive than the bacterial methods which have been successfully applied in the past, the hæmoglobin method (originally used by Hoppe-Seyler to demonstrate oxygen from green plants) has the advantage of giving the measure of oxygen. A solution of hæmoglobin containing 0.45 × 10⁴ gm. atoms of iron per litre, is equivalent to 1 c.mm. of oxygen per c.c.; the degree of saturation can be determined spectroscopically with an accuracy of 5 per cent.