Cumulative Clicker Practice Test 2025 – The Definitive All-in-One Study Guide for Success!

The chosen sequence accurately represents the events occurring during muscle contraction within a sarcomere. It begins with the activation of the myosin heads, which is facilitated by ATP hydrolysis. This provides the energy necessary for the myosin heads to bind to the actin filaments, initiating the cross-bridge cycle.

Following the formation of the cross-bridges, the myosin heads pivot and pull the actin filaments toward the center of the sarcomere, a process often referred to as the power stroke. This action shortens the sarcomere, contributing to muscle contraction.

As the cycle continues, the myosin heads detach from the actin after a new ATP molecule binds to the myosin, allowing the heads to re-cock or reset for another cycle. The sequence concludes with detachment of the myosin from the actin, readying the system for the next contraction cycle.

This accurate sequence mirrors the physiological mechanisms of muscles, particularly during sarcomere contraction, making it a well-understood representation of the sliding filament theory.