Answer:
Electron transport chain is the representation of the movement of an electron through electron acceptors which itself gets reduced on the path during both cellular respiration and photosynthesis.
The electron transport chain is important to cell as it helps the cell to produce energy currency molecule of the cell called ATP.
The transfer of electon through the electron transport chain help generate the membrane potential across the membrane which when tries to equilibrate forms the ATP molecules in the cell. The ATP is utilised in performing other metabolic processes.
Thus, this process is important for the production of the ATP in both the process.