Fig. 7.

Representative traces of O₂ concentration for 0 (solid black line) and 0.60 mM (solid blue line) CaCl₂ without added MgCl₂ (A) or with 1 mM MgCl₂ (B) in response to adding PA, CaCl₂, and ADP as shown in the timeline scheme (Fig. 1). Dotted lines are the first derivatives showing the maximal rates of change during state 3. Calculated mean O₂ consumption rates (C,D) increased in the presence 0.25 mM CaCl₂ during state 3 respiration; higher [CaCl₂] did not increase state 3 respiration further. Adding MgCl₂ attenuated state 3 respiration. Adding MgCl₂ enhanced state 4 respiration at all [CaCl₂], which was compatible with the decreased NADH during state 4 respiration (Fig. 6). See Fig. 9 for statistics.