Question: In metabolically active cells, protons are pumped out of the mitochondrial such that the pH of the mitochondrial matrix is ?8 compared with the neutral pH (approximately 7) of the intermembrane space and cytosol. The following equation calculates free energy stored in proton concentration gradient across the membrane:
G= R T ln[H+]in/[H+]out,?
where [H+]in and [H+]out refer, respectively, to the proton concentrations inside and outside the mitochondria inner membrane. R is the gas constant 1.98 x 10I3 kcal/mol/deg, T is the absolute temperature in kelvins=298?K. Note that ln (X) = 2.3 log10(X). ?
Assume that the electric potential across the inner mitochondrial membrane is dissipated, so the electrochemical gradient is composed solely of a proton concentration gradient. Calculate the free energy stored in this gradient. Please show your work.