Question

o Each crossbridge goes through crossbridge cycles independently of other crossbridges. o What are the four things that the crossbridge cycle is dependent on? o What is the difference between the cocked and uncocked position of a crossbridge? o Define the term cocking. o ATP hydrolysis by myosin causes: Cocking Storage of energy within the crossbridge An increase in affinity of myosin for G actin o The ADP and P, created during ATP hydrolysis remain bound to the crossbridge for a short time before they are released. . Which is released first: ADP or P? What is the result of this release? Which is released second: ADP or P;? What results from this release? o What decreases the affinity of myosin for G actin?

Answer 1

Cocking is defined as tilting in a particular direction.

After the ATP hydrolysis the ADP and Pi are formed among the at first the Pi is released

After the binding of myosin to actin the the Pi is released and the myosin undergoes a confirmational change to lower energy state. As myosin expends energy, it moves through the power stroke pulling the actin filament towards the Moline

At the end of the power stroke the myosin is at low energy position.

After the power stroke, ADP is released but the cross bridge is still in place.