Chemiosmosis and ATP synthase Original Scenario-Based Download PDF

Questions

1. 1.

   A synthetic biology team engineers a strain of microalgae with a modified mitochondrial inner membrane containing light-gated uncoupling channels. When illuminated by green light, these channels open, allowing protons that were pumped into the intermembrane space to diffuse directly back into the mitochondrial matrix without traversing ATP synthase. Throughout this illumination, electron transport complexes continue to oxidize electron donors and consume oxygen at high rates. What is the immediate consequence of this green light activation on the cell's energetic process?

   • A) The electron transport chain shuts down entirely because oxygen cannot accept electrons without an existing proton gradient.
   • B) ATP synthase reverses direction to pump ADP and inorganic phosphate out of the matrix into the intermembrane space.
   • C) The proton-motive force collapses, drastically reducing ATP synthesis while energy from electron transfer is dissipated as heat.
   • D) Protons become trapped in the intermembrane space, raising the acidity of the cytosol and inhibiting glycolysis enzymes.