“Rate Limiting” Resistances and Photosynthesis

Abstract

WHEN carbon dioxide is assimilated by illuminated green leaves it diffuses as a gas into the leaves from the leaf boundary layer, through the stomatal pores and intercellular spaces; it then dissolves in the water films of the mesophyll cell walls and moves in the liquid phase across membranes and within the cytoplasm to the chloroplasts, where it is chemically incorporated into acceptor substances¹. Recent work^2–5 has led to apparently contradictory conclusions concerning the relative importance of these resistances in the path of carbon dioxide.