TABLE 2.

Criteria used to determine the best fits in each trial

The experimental data in Fig. 2 showed both an inflection point (below 50% reduction of cytochrome b₅₆₆) and a peak (between 70 and 80% reduction of b₅₆₆). Therefore, the best model fits were selected based on four criteria as follows: 1) presence of an inflection point; 2) presence of a peak; 3) best least squares fit of the line to the raw data in Fig. 2 with no extra weighting, calculated using only the first term in Equation 4; 4) best least squares fit of the line to the raw data in Fig. 2 with extra weighting as described under “Experimental Procedures,” calculated using Equation 4. The presence or absence of inflections and peaks in the superoxide production rate curves was determined by numerical differentiation and root search to ensure objectivity.

Trial	Criterion
	Inflection	Peak	Unweighted least squares error (truncated Equation 4)	Weighted least squares error (full Equation 4)
1	No	No	8.9	9.2
2	No	No	8.9	9.2
3	Yes	Yes	0.95	1.7
3+ATP	Yes	Yes	2.9	3.4
4	Yes	Yes	0.93	3.4