Fig. 3

Sterol abundance in the PM and steady state sterol flux across the PM decrease non-linearly with increasing q₂. Steady state sterol abundance in the PM (a S_T, sum of Eq. 14a, 14b) and steady state sterol flux across the PM (b Eq. 16) as function of the passive sterol distribution between both PM leaflets (q₂) for the indicated rate constants of intracellular sterol release (k₃). Other parameters were v₁ = 1 mol/s and k_− 2 = 1 s^− 1, respectively. See text for further explanations