FIGURE 4.

Effect of NADH photolysis on pH. The solution pH was followed from SNARF fluorescence. Experiments were conducted on 1 mM in pure water in the absence of additional pH buffers. Experiments were conducted in the presence of oxygen, oxygen and oxidized cyto_c (20 mM), or oxidized cyto_c alone (nitrogen environment). As predicted from the equations in Fig. 3, the photolysis of NADH was associated with an increase in pH in oxygen, whereas in the presence of cyto_c a net decrease in pH was observed.