Final answer:
The F1 subunit of ATP synthase is composed of α and β subunits arranged alternately, with the F1γ subunit rotating within and causing conformational changes essential for ATP synthesis. The F0b subunit prevents the whole F1 complex from rotating, facilitating the energy conversion needed for ATP production.
Step-by-step explanation:
The F1 subunit of ATP synthase is characterized by a complex assembly of proteins that plays a crucial role in ATP synthesis. Specifically, it has a set of three α and three β subunits, arranged alternately like the carpels of an orange, forming a complex abbreviated as F1(αβ)3. In the middle of this complex is the F1γ subunit, which rotates within the F1(αβ)3 complex. This rotational movement is linked to conformational changes in the three β subunits that catalyze ATP synthesis. The rotation of the F1γ subunit causes changes in the F1β subunits, which directly contribute to the mechanism of ATP synthesis. Meanwhile, the F0b subunit prevents the F1(αβ)3 complex from rotating, while the F1γ subunit rotates with the rotor F0c ring as protons flow through the channels of the F0 part, which is embedded in the membrane. This entire process resembles a turbine being moved by water in a hydroelectric dam, with the energy conversion facilitating the synthesis of ATP.