Question

what generates the force that shortens the sarcomeres to bring about muscle contraction? cross - bridges dissociating from actin filaments troponin pulling on the tropomyosin myosin cross - bridges pulling on the actin filaments atp binding to myosin heads need help? review these concept resources. rate your confidence to submit your answer. high medium low reading © 2025 mcgraw hill. all rights reserved. privacy center terms of use

Explanation:

During muscle contraction, myosin cross - bridges form with actin filaments. The myosin cross - bridges then pull on the actin filaments, which shortens the sarcomeres and causes muscle contraction. Cross - bridges dissociating from actin filaments is part of the relaxation process. Troponin and tropomyosin are involved in regulating the interaction between myosin and actin but do not directly generate the force for contraction. ATP binding to myosin heads is an energy - related step for the cross - bridge cycle but not the force - generating step itself.

Answer:

Myosin cross - bridges pulling on the actin filaments