Chloroplasts in envelopes: CO(2) fixation by fully functional intact chloroplasts

Dan Arnon, Bob Whatley, Mary Belle Allen, and their colleagues, were the first to obtain evidence for 'complete photosynthesis by isolated chloroplasts' albeit at rates which were 1% or less of those displayed by the intact leaf. By the 1960s, partly in the hope of confirming full functionality, there was a perceived need to raise these rates to the same order of magnitude as those displayed by the parent tissue. A nominal figure of 100 mumol/mgcchlorophyll/h (CO(2) assimilated or O(2) evolved) became a target much sought after. This article describes the contributions that Dick Jensen and Al Bassham [(1966) Proc Natl Acad Sci USA 56: 1095-1101], and my colleagues and I, made to the achievement of this goal and the way in which it led to a better understanding of the role of inorganic phosphate in its relation to the movement of metabolites across chloroplast envelopes.