Compounds Interfering with ATP Synthesis

Abstract

In a respiratory system, the mitochondrial electron transport coupled with oxidative phosphorylation is the important step to produce ATP which is vital to any organism and vulnerable to pesticides. During various steps in the glycolysis and the tricarboxylic acid cycle, NAD is reduced to NADH. Also, flavin adenine dinucleotide (FAD) is reduced to FADH₂ when succinate is converted to fumarate during the tricarboxylic acid cycle. These two cofactors are reoxidized by passing their reducing power ( H+ + electron) through the mitochondrial electron transport system, eventually to oxygen, reducing it to water (Fig. 17.1). The electron transport system divided into four complexes ( I, II, III, IV) and flavin mononucleotide (FMN), FAD, FeS, coenzyme Q, and cytochromes (b, c₁, c, a, a₃), constitutes a respiratory carrier chain. The reactions produce energy at the indicated sites, which is utilized for ATP formation from ADP and inorganic phosphate.