Uptake of glucose, pyruvate and malate into isolated tomato fruit chromoplasts. Chromoplasts were incubated in the presence of the indicated concentrations of glucose (A), pyruvate (B) and malate (C) containing 3.125 Bq of [14C]-glucose, [14C]-pyruvate and [14C]-malate, respectively. Dotted lines in graphs (B) and (C) correspond to chromoplasts preloaded with Na+ and inorganic phosphate, respectively. Each value represents the mean and standard deviation of measures made with three separate preparations. Values are the mean +/- SE of duplicate measurements made with three independent chromoplast preparations.