A dog paddles across a lake that would happen to the dog if the hydrogen ion pumps in its mitochondria stopped functioning

The dog will be deprived of ATP supply.

Explanation:

Mitochondria is the site of ATP production through the oxidation of fuels by aerobic cellular respiration. Electron transfer from reducing powers NADH and FADH2 to the molecular oxygen also generates a concentration gradient of protons across the inner mitochondrial membrane by pumping the protons towards intermembrane space through proton pumps.

The energy of this concentration gradient is used to drive ATP synthesis as protons are being transported back to the matrix. If the proton pumps have stopped working, the proton concentration gradient would not be generated and the dog will not be able to get energy from aerobic cellular respiration.

The dog would not have any energy left for activity