5.4 Electron Transport System
Module 5 ~ Lesson 5
Electron Transport System
The oxidation of NADH and FADH2 create a proton gradient that powers ATP synthase. This is called chemiosmosis and, similar to chemiosmosis in photosynthesis, involves the movement of hydrogen ions down a concentration gradient.
Oxygen acts as the final electron acceptor in the electron transport system. Without oxygen, the NADH and FADH2 remain in their reduced state, and no NAD+ or FAD would be available for the Kreb's cycle.
Below is a pictorial representation of each step of aerobic cellular respiration. Most of the ATP is created in the electron transport system.