Fig. 6.

Effects of inner membrane morphology and surrogate kinase activity on (A,B) flux of ATP synthase, J(AS) and (C) ATP output. qATP. Graphs summarize results of computer simulations run with reduced BioModel and 3D spatial models (Fig. 5) of increasing size, as described in text.

(A) Decrease in J(AS) as a function of crista length, calculated as the diagonal from the center of the junction opening to the farthest corner of the crista surface. Data for lamellar crista are represented by ☐ and tubular cristae by ◯; closed symbols correspond to the smaller forward rate constant for the surrogate kinase (k_f ​= ​0.003 ms⁻¹) and open symbols to a three fold larger rate constant (k_f ​= ​0.009 ms⁻¹), labelled “slow” and “fast”, respectively. Solid trend lines correspond to data for lamellar cristae and dashed trend lines for tubular cristae.

(B) Decrease in J(AS) as a function of extent of inner membrane folding; symbols and trend lines as in (A).

(C) ATP output, qATP ​= ​J(AS) × inner membrane area, as a function of relative model volume (largest volume ​= ​0.099 ​μm³). There are two models with three fold volume increase (i.e., V_MIT ​= ​3) relative to the original. Data on left corresponds to model with threefold larger crista width (z × 3); data on right to threefold larger crista length (y × 3).