Also, during the ETC, the electrons pass down the proteins to oxygen to make water. O2 + H = H2O
During Oxidative Phosphorylation, the hydrogen ions get so tightly packed in the intermembrane space. They have no way out other than through the ATP Synthase. The go through the ATP Synthase and as they do, 32 ATPs are made because a phosphate is attached to ADP.
Summary: Cellular Respiration consists of Gylcolysis, Krebs Cycle, and Oxidative Phosphorylation. This whole process is how food is broken down to make energy.