Question

what is the purpose of the electron transport chain (etc) in cellular respiration? producing water from oxygen gas catalysing substrate - level phosphorylation transferring electrons to nadh and fadh₂ using energy from electrons to drive the formation of a proton gradient catalysing redox reactions i dont know yet

Explanation:

The electron transport chain (ETC) in cellular respiration uses the energy from electrons (carried by NADH and FADH₂) to pump protons (H⁺) across a membrane, creating a proton gradient. This proton gradient is then used to drive ATP synthesis (chemiosmosis).

• Producing water from oxygen gas is a by - product of the ETC (when oxygen acts as the final electron acceptor), not its main purpose.
• Substrate - level phosphorylation occurs in glycolysis and the citric acid cycle, not the ETC.
• NADH and FADH₂ transfer electrons to the ETC, not the other way around.
• While redox reactions occur in the ETC, the main purpose is to establish a proton gradient for ATP production.

Answer:

Using energy from electrons to drive the formation of a proton gradient.