Where are the enzymes for the $ETS$ (Electron Transport System) found in the mitochondria?

Describe: Electron Transport System $(ETS)$ and oxidative phosphorylation.

Oxidative phosphorylation refers to

Given below are two statements.
Statement-$I$: During aerobic respiration,$ETS$ regenerates co-enzymes such as $NAD^+$ and $FAD^+$ from their reduced forms $NADH + H^+$ and $FADH_2$.
Statement-$II$: During aerobic respiration,$ETS$ generates a major amount of energy in the form of $ATP$ molecules.
In the light of the above statements,choose the correct answer from the options given below.

Protons for the formation of $ATP$ first pass from:

Which of the following is common to both respiration and photosynthesis?