Question

A newly developed insecticide compound steals high-energy electrons from FADH2 and NADH before they can bind to the electron transport chain. Why does this kill insects?
1. glycolysis reactions are blocked
2. fermentation pathways will be switched on, supplying insufficient ATP to maintain the insect
3. The ETC cannot establish a proton gradient to drive chemiosmotic production of ATP
4. the citric acid cycle cannot proceed

Answer 1

Answer:

3. The ETC cannot establish a proton gradient to drive chemiosmotic production of ATP

Explanation:

Reduction of FAD+ and NAD+ during glycolysis and Kreb's cycle produces FADH2 and NADH respectively which in turn give their electrons to the molecular oxygen via electron transport chain (ETC). This electron transfer is accompanied by the pumping of protons towards the inter-membrane space resulting in the generation of an electrochemical gradient.

The energy of the electrochemical gradient is harnessed to drive ATP synthesis. The process is called chemiosmotic ATP synthesis. The mentioned insecticide would not allow the FADH2 and NADH to reduce oxygen and no electrochemical gradient is developed to drive the chemiosmotic production of ATP.