(A–B) OXPHOS kinetics (via CK clamp) were assessed in the absence of adenylates or in the presence of minimal ΔGATP (−54.16), maximal ΔGATP (−61.49), or maximal ΔGATP + CAT (Carboxyatractyloside; ANT inhibitor). Comparison of OXPHOS kinetics in MV-4–11 (A) and HL-60 cells (B). (C) Ratio of FCCP ΔGATP to JH+OXPHOS with and without CAT in MV-4–11 and HL-60 cells. (D) OXPHOS kinetics measured in the presence of CAT in mitochondria isolated from MV-4–11. (A–D) n = 4 independent experiments per cell type. (E) Mitochondrial membrane potential (ΔΨ) in PBMC isolated mitochondria across a ΔGATP span, followed by CV inhibition with oligomycin; n = 8 independent experiments. (F) Representative trace of ΔΨ in HL-60 isolated mitochondria across a ΔGATP span, followed by ANT inhibition with CAT. (G) Quantification of the experiment depicted in panel F in HL-60 and KG-1 isolated mitochondria; n = 3 independent experiments. (H) Mitochondrial ΔΨ in MV411 isolated mitochondria across a ΔGATP span, followed by CV inhibition with oligomycin; n = 9 independent experiments. (I) Mitochondrial ΔΨ in isolated mitochondria across a ΔGATP span in the absence of any carbon substrates; n = 4 independent experiments. (J) Ratio of group mean ΔΨ generated at ΔGATP = −61.49 kJ/mol in the absence versus presence of carbon substrates (pyruvate, malate). Data are presented as mean ± SEM and analyzed by two-way ANOVA (A–B, I) or paired t-tests (C–E, G–H). *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001.