Unit C

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.


Watch the following video and complete the quiz questions.