Cross bridge cycle and binding sites on actin Cross bridge cycling continues as long as the myosin binding sites on actin are exposed. What is name given to the regularly spaced infoldings of the sarcolemma? What event causes cross bridge detachment?
What causes cross bridge detachment? Definition Sarcomere Shortening: How to study your flashcards. There are always some myosin heads attached to the actin myofilament when other myosin heads are detaching. This can only happen in the presence of calcium, which is kept at extremely low concentrations in the sarcoplasm.
As soon as the cross bridge forms, the power stroke occurs, moving the thin filament toward the center of the sarcomere.
Ach crosses synapse where it binds with receptors on motor end plate causing:. Study these flashcards. After a power stroke, the myosin head must detach from actin before another power stroke can occur.
You've reached the end of this preview. Cram has partnered with the National Tutoring Association Claim your access. Resting muscles store energy from ATP in the myosin heads while they wait for another contraction. The energy comes from the hydrolysis of GTP. Nerve Side: The binding of ATP to the myosin head weakens the bond between myosin and actin, forcing the myosin head to detach.
Excitation, in this case, refers to the propagation of action potentials along the sarcolemma.
Where in the cross bridge cycle does ATP hydrolysis occur? The hydrolysis of ATP is required for the cocking of the myosin head. In tug-of-war, individual hands release after they pull on the rope, but not all hands release at the same time. What specific event initiates the contraction?
ATP binding to the myosin head. What specific event triggers the uncovering of the myosin binding site on actin? Myosin head activation During a cross bridge cycle, a myosin head binds to actin.
Which of the following is most directly responsible for the coupling of excitation to contraction of skeletal muscle fibers? A myosin head binds to which molecule to form a cross bridge? Sign up here.