I like to approach this in 6 steps, but you could also draw this as a diagram if you find that more helpful. All the words in capital letters are needed to get the credit in an exam: 1)NADH and FADH are REOXIDISED when hydrogen atoms are donated to ELECTRON CARRIERS. the hydrogen atoms are then SPLIT INTO PROTONS AND ELECTRONS. 2)The FIRST ELECTRON CARRIER accepts the electrons. The protons go into SOLUTION in the MATRIX. 3) The electrons are passed along an ELECTRON TRANSPORT CHAIN of ELECTRON CARRIERS. This releases energy. The electrons are then donated to MOLECULAR OXYGEN, which is the FINAL ELECTRON ACCEPTOR. 4) Energy generated by this flow of electrons is used by COENZYMES associated with complexes 1, 3 and 4 to PUMP PROTONS ACROSS THE INTERMEMBRANE SPACE. This creates a PROTON GRADIENT. 5) The protons flow DOWN THE PROTON GRADIENT, through ion channels associated with ATP SYNTHASE. This is CHEMIOSMOSIS. This DRIVES THE ROTATION of part of the ATP synthase, which joins ADP and phosphate to generate ATP. 6) Protons are also passed to MOLECULAR OXYGEN, which is REDUCED to form WATER.