Kinetics of Photosynthesis and Allied Processes

Abstract

THE photosynthetic process in the living plant consists of two separate reactions, namely, the primary photosynthetic reaction which has no temperature coefficient, and the dark or Blackman reaction which restores the conditions disturbed by the primary reaction and has a temperature coefficient. The velocity of the primary reaction is proportional to the concentration of the chlorophyll on the irradiated surface, the intensity of light and the concentration of the hydrated carbon dioxide. If these factors be denoted by a, I and P, respectively, the initial velocity will be expressed by k₁aIP, and the velocity at time t will be k₁IP(a x). The dark reaction is known to be unimolecular, and its velocity at time t will be k₂xe^Q/RT. It is obvious that a photostationary state will be established when the velocities of the primary and Blackman reactions become equal, and if this state be established at time t, then the observed rate of photosynthesis will be given by