ETC is consisting of four large multiprotein complexes embedded in the inner mitochondrial membrane to form a gradient of protons that leads to the creation of adenosine triphosphate ATP.
This process takes place in mitochondria in both cellular respiration and photosynthesis.
ATP is used by the cell for functioning cellular activities.
The end products of the ETC or electron transport chain are the formation of ATP, NAD+, FAD, water, and protons.
ETC works as a proton pump since it pumps hydrogen ions or protons through the membrane, and only allows ATP synthase for the formation of ATP.