Question

Shown below is the ATP hydrolysis cycle of a motor protein. What sentence BEST describes the state of the motor protein in "C"?

a) The hydrolysis of ATP to ADP caused a conformational change in the protein.
b) The binding of ADP and inorganic phosphate displaced ATP.
c) The release of ADP led to a forward shift of the protein along the filament.
d) The binding of ATP activated the protein for movement.

Answer 1

The motor protein in state 'C' has undergone a conformational change due to ATP hydrolysis, catalyzed by ATPase, resulting in the myosin head being in a cocked, high-energy position, ready for another cycle.

Step-by-step explanation:

The question asks about a motor protein's ATP hydrolysis cycle, specifically the motor protein's state at point 'C'. The best description for the state of the motor protein in 'C' is: The hydrolysis of ATP to ADP caused a conformational change in the protein. This process involves the enzyme ATPase present in the myosin, which catalyzes the conversion of ATP to ADP and inorganic phosphate. This, in turn, induces a change in the angle of the myosin head to a 'cocked' position that is high-energy and poised for another interaction with actin, therefore storing the energy required for movement.