Question

When H+ gets pumped by ATP synthase, is it transported via facilitated diffusion through the F1 subunit? This is what activates the enzymatic subunit, F0, to hydrolyze and generate ATP.

Answer 1

The flow of H+ ions through ATP synthase occurs through the F0 subunit and provides the energy required for the F1 enzymatic subunit to synthesize ATP from ADP and inorganic phosphate. This process is known as chemiosmosis and is part of oxidative phosphorylation.

Step-by-step explanation:

The student question seems to conflate the function of the components in ATP synthase. In truth, when H+ ions are pumped by ATP synthase, they pass through the F0 subunit, not the F1 subunit. The F0 acts as a channel that allows chemiosmosis, where H+ ions flow back into the mitochondrial matrix from the intermembrane space, following their electrochemical gradient. This flow causes mechanical rotation in the ATP synthase complex, which then activates the enzymatic portion, the F1 subunit, to catalyze the synthesis of ATP from ADP and inorganic phosphate. This process does not involve facilitated diffusion through the F1 subunit, nor does it involve F0 in hydrolyzing ATP.

ATP synthase functions akin to a hydroelectric dam's turbine, harnessing the potential energy from the electrochemical gradient of protons (H+). This energy is translated into the mechanical energy needed to synthesize ATP, a process known as oxidative phosphorylation. Therefore, it's the flow of hydrogen ions through the ATP synthase, particularly the F0 component, that provides the energy for ATP synthesis, not an activation of the enzymatic unit for ATP hydrolysis.