Question

Which of the following sequences is in the correct order for the cyclic process by which a myosin head generates force on an actin filament for muscle contraction?

A) power stroke, crossbridge formation, crossbridge dissociation, cocking of myosin head
B) crossbridge formation, power stroke, crossbridge dissociation, cocking of myosin head
C) crossbridge formation, cocking of myosin head, power stroke, crossbridge dissociation
D) crossbridge formation, crossbridge dissociation, cocking of myosin head, power stroke
E) crossbridge formation, power stroke, crossbridge dissociation, power stroke, cocking of myosin head

Answer 1

The correct order for the cyclic process of myosin generating force on an actin filament for muscle contraction is crossbridge formation, power stroke, crossbridge dissociation, and cocking of the myosin head.

Step-by-step explanation:

The correct order of the cyclic process by which a myosin head generates force on an actin filament for muscle contraction is:

1. Crossbridge formation: The myosin head attaches to the actin filament.
2. Power stroke: The myosin head bends and moves the actin filament inward, shortening the sarcomere.
3. Crossbridge dissociation: ADP and inorganic phosphate are released, but the myosin head remains attached to actin.
4. Cocking of myosin head: Another ATP binds to the myosin head, causing it to detach from actin and return to a high-energy position.