The input and output of the electron transport chain are NADH + FADH2 for the input, and 34 or 36 ATP for the output. The electron transport chain is the last stage of cellular respiration. Electron Transport Chain can be abbreviated into ETC sometimes. You can find the ETC inside the mitochondrion.
It is an aerobic process, which means that it needs the energy to perform its functions. This transport chain of electron takes place in the cristae of the mitochondria's inner membrane. In this particular step of cellular respiration, NADH and FADH2 carry electrons and drop them off from the citric acid cycle.
When the electrons are dropped off, it gives a chance for the formation of a large amount of ATP molecules. As a matter of fact, 34 ATP is definitely produced. The electron transport chain converts oxygen directly to water after usage, which shows that it is directly aerobic.