Kinetic Relationships Between Photosynthesis and Respiration in the Algal Flagellate, Ochromonas Malhamensis.

Abstract

The relation of photosynthesis to respiration in the alga O. malhamensis was studied by analysis of the gaseous atmosphere over an actively metabolizing cell suspension subjected to various conditions in light and dark. The atmosphere was enriched with isotopic O2 and CO2 and measurements were made of the rates of consumption and production of these gases using a recording mass spectrometer. At low light intensities, photosynthesis had little effect on O2 consumption, whereas higher intensities were stimulatory. CO2 production was inhibited even in very dim light and with increasing intensity no further depression of CO2 production occurred. This behavior was explained by competitions between substrate generated and light generated reductant for electron acceptors of the respiratory chain.