Fig. 2 shows the effect of nutritional status on the activity of oxidative phosphorylation in pectoral muscle mitochondria respiring on pyruvate (Fig. 2A) or palmitoyl-l-carnitine (Fig. 2B). The maximal rates of oxygen consumption and ATP production, the highest points to the right of the linear relations (Fig. 2A,B), and the apparent affinity constants of mitochondrial fluxes (oxygen consumption or ATP synthesis) in response to added ADP (supplementary material Fig. S1) were not significantly different between groups.