Question

ATP can only be synthesized when the subunit it occupies (in ATP synthase) is in the ___ state.

Answer 1

Answer:

The T state.

Explanation:

The synthesis of ATP in the organisms is mediated by the ATP synthase. ATP Synthase enzyme contains the two subunits called CF₀ and  CF₁.  

The mechanism of ATP synthesis is known as the binding chain mechanism or flip flop mechanism as the synthesis of ATP is coupled with conformation changes of CF₁ units.

When the electrons move through CF₀, it rotates the γ-subunit of the CF₁ which further rotates the nucleotide-binding sites of β-subunit. The binding sites contain three conformational states which interconvert which are O empty state, L or loose state which binds ATP and Pi and T tight state which binds ATP. The T state of the ATP molecule binds the ADP and Pi to ATP.

Thus, the T state is the correct answer.