Chapter 23, Problem 23.81EP

Interpretation Introduction

Interpretation: To determine the two substances that provide electrons for the operation of the electron transport chain.

Concept introduction: Electron transport chain is a sequence of biochemical reactions in which electron and hydrogen from the citric acid cycle is transferred to various intermediate carriers and finally reacted with molecular oxygen and leads to the formation of water. The reaction of the formation of the water is:

${\text{O}}_2+4e^{-}+4{\text{H}}^{+}\to 2{\text{H}}_{\text{2}}\text{O}$

Energy is lost during the transfer of the electrons from one intermediate carrier to another intermediate carrier and that energy is used for the preparation of ATP from ADP.