Question

1) According to the chemiosmotic theory, the synthesis of 1 mole of ATP is coupled to the movement of 4 moles of H ions across the inner mitochondrial membrane (from outside to inside). Both the pH and the electrostatic potential (φ) can be different on different sides of the cell membrane as maintained by metabolic processes. a) Derive an expression for AG for the movement of 4 moles of H from outside the membrane to inside the membrane. Your expression should be written in terms G for the synthesis of I TP is 31.4 kJ, how large a pH gradient (ApH) must be present for the transport of 4 moles of H to drive ATP formation when (T-25°C): iii) Δφ=+0.15V?

Answer 1

Since movement is across both concentration and voltage gradient, the Gibbs free energy change will be,

Hout ie Po the piocess is and

b) RT ΔΡΗ = 12.66て z (8314 χ298-15)0pH-9648 16. 56 8 314 x 293.1S 4 8e xor 1s31400-1441 8ふtx298-15