An account of the author's life and scientific research is presented.
Two main lines of research have been pursued: (1) Studies on the physi
ological aspect of photosynthesis started from experiments with crops
under field conditions and then extended to the study of photosynthesi
s in nature; and (2) studies on the mechanism of photophosphorylation
and related problems which began with the measurement of quantum requi
rement of photophosphorylation. This work led to the discovery of the
'high energy state' of phosphorylation and many other interesting find
ings. In recent years, efforts have been made to study the operation a
nd regulation of photosynthetic apparatus with a view to link the abov
e-mentioned lines of research together.