Multiple Choice
In skeletal muscle contraction, a skeletal muscle fiber deprived of adequate ATP supplies will most likely:
28
views
8. Protein Function
Skeletal Muscle Contraction
Multiple Choice
In skeletal muscle contraction, what is the primary role of ATP in the cross-bridge cycle?
A
It directly provides the force for the power stroke without needing to be hydrolyzed.
B
It is hydrolyzed by actin to pump into the sarcoplasmic reticulum.
C
It binds to troponin C to move tropomyosin away from actin’s myosin-binding sites.
D
It binds to myosin to detach myosin from actin, allowing the cross-bridge cycle to continue.
Verified step by step guidance1
Understand the cross-bridge cycle in skeletal muscle contraction, which involves interactions between actin and myosin filaments powered by ATP.
Recognize that ATP binds to the myosin head after the power stroke, causing a conformational change that leads to the detachment of myosin from actin.
Know that ATP is then hydrolyzed by the myosin ATPase activity, which energizes the myosin head, preparing it for the next cycle of binding and pulling on actin.
Clarify that ATP does not directly provide the force for the power stroke; instead, the energy from ATP hydrolysis is used to reset the myosin head.
Note that ATP does not bind to troponin C nor is it hydrolyzed by actin; its primary role is to enable myosin detachment from actin, allowing continuous muscle contraction cycles.
Related Videos
Related Practice
