Electron transport chain Original Scenario-Based Download PDF

Questions

1. 1.

   During an exploratory mission to an icy moon, researchers analyze a newly discovered bio-construct that utilizes an electron transport chain functionally identical to that of eukaryotic mitochondria. When an environmental toxin specifically prevents the transfer of electrons from Complex IV to molecular oxygen, the entire electron carrier pathway becomes immobilized. Which of the following immediate consequences will be observed across the inner membrane of these organelles?

   • A) The concentration of protons in the intermembrane space will surge, dramatically accelerating ATP synthase activity.
   • B) The proton gradient across the inner membrane will dissipate as proton pumping ceases, leading to a shutdown of ATP synthesis.
   • C) NADH and FADH2 will donate their electrons at higher rates to overcome the thermodynamic blockage at the terminal complex.
   • D) Water formation will rapidly accelerate within the mitochondrial matrix to consume surplus accumulated protons.