Which parts of the atp synthase act as rotors during atp synthesis?

Ring and y subunit

Explanation:

ATP synthase is an enzyme that is integrated in the mitochondrial membrane. The ATP synthase utilizes the energy of the protons to synthesize the ATP molecules.

The ATP synthase enzyme is composed of two units: the Fo unit and the F1 unit. The F1 unit is composed of α, B, γ, δ, and ε subunits, forms the rotor and face the cytoplasmic portion whereas the Fo unit is integrated into the membrane and acts as a pump.

When the proton moves through the pump then the rotor utilizes the energy of the proton and the γ subunit moves the rotor or changes the conformation which converts the ADP into ATP.

Thus, Ring and y subunit is correct.