Final answer:
Damage to complex II in the electron transport chain would decrease the proton concentration in the intermembrane space as it impairs the transfer of electrons and the functioning of the ETC, leading to a reduction in ATP synthesis.
Step-by-step explanation:
If complex two were damaged in the electron transport chain (ETC), the proton concentration would not remain the same because complex II is crucial for transferring electrons from FADH2 to ubiquinone. This in turn helps to maintain the proton gradient necessary for ATP synthesis. Damage to complex II would mean that ubiquinone would not pass electrons from complex I and II to complex III, leading to a cessation of the proton pumping mechanism and a subsequent decrease in proton concentration across the membrane.
The free energy release would be directly affected if a cytochrome failed to undergo one of the redox reactions. Free energy carried by the electrons is used to pump protons across the membrane, creating a proton motive force. This force drives the synthesis of ATP, so if the redox reaction fails, less ATP would be produced.
In prokaryotes, as electrons are transferred through an ETS, H+ is pumped out of the cell. Therefore, a disruption in the ETC such as the damage of a complex affects proton pumping and overall energy production in the cell.