Chapter 8, Problem 36A

Summary Introduction

Introduction :

The electron transport system is the terminal step of aerobic respiration that operates on the inner membrane of the mitochondria. During electron transport, high-energy electrons are released from NADH and FADH₂to produce energy in the form of ATP. Oxygen is the final electron acceptor in the electron transport system in cellular respiration. Protons and electrons are transferred to oxygen to form water.

Answer to Problem 36A

Correct answer :

The correct answer is option (A) H₂O.

Explanation of Solution

Explanation/justification for the correct answer :

Option (A) H₂O (water). At the end of the electron transport system, two protons, two electrons, and half of an oxygen molecule combine to form H₂O( water). Thus, the correct answer is an option (A).

The explanation for the incorrect answer :

Option (B) O₂ (oxygen). Free oxygen as the final electron acceptor of the electrons which are removed from the intermediate compounds NADH and FADH₂ .Thus, this is an incorrect option.

Option (C) CO₂. CO₂ (carbon dioxide) is not produced when the electrons leave the electron transport chain in cellular respiration. It is not a part of electron transport chain. Thus, this is an incorrect answer.

Option (D) CO. CO (carbon monoxide) is not produced when the electrons leave the electron transport chain in cellular respiration. It is not a part of electron transport chain. Thus, this is an incorrect answer.