Elevated levels of Pi in the sarcoplasm of skeletal muscle fibers would decrease the release of Pi from myosin. What direct impact would this have on the cross bridge cycle? troponin wouldn't be able to bind myosin if Pi isn't released myosin wouldn't be able to initiate the power stroke if Pi isn't released the muscle wouldn't be able to relax if Pi isn't released myosin wouldn't be able to bind to actin if Pi isn't released

Elevated levels of Pi in the sarcoplasm of skeletal muscle fibers would decrease the release of Pi from myosin. What direct impact would this have on the cross bridge cycle? troponin wouldn't be able to bind myosin if Pi isn't released myosin wouldn't be able to initiate the power stroke if Pi isn't released the muscle wouldn't be able to relax if Pi isn't released myosin wouldn't be able to bind to actin if Pi isn't released

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter8: Muscle Physiology

Section: Chapter Questions

Problem 12RE

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Similar questions

The _____ is the basic unit of muscle contraction. a. myofibril b. sarcomere c. muscle fiber d. myosin filament
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When ADP and Pi are bound to myosin in the cross-bridge cycle... (MULTIPLE SELECT) A. There is no force production and myosin is not bound to actin B. There is no force production and myosin is bound to actin C. There is force production and myosin is not bound to actin D. If its smooth muscle, a second phosphate might be bound to the light chain E. The cross-bridge is in a state of rigor mortis F. There is force production and myosin is bound to actin
Which of these statements about the molecular structure of myofilaments is true?a. Tropomyosin has a binding site for Ca2+.b. The head of the myosin molecule binds to an active site on G actin.c. ATPase is found on troponin.d. Troponin binds to the rodlike portion of myosin.e. Actin molecules have a hingelike portion, which bends and straightensduring contraction.
Why is the latent period longer during an isotonic twitch of a skeletalmuscle fiber than it is during an isometric twitch?a. Excitation–contraction coupling is slower during an isotonic twitch.b. Action potentials propagate more slowly when the fiber is shortening,so extra time is required to activate the entire fiber.c. In addition to the time for excitation-contraction coupling, it takesextra time for enough cross-bridges to attach to make the tension in themuscle fiber greater than the load.d. Fatigue sets in much more quickly during isotonic contractions, andwhen muscles are fatigued the cross-bridges move much more slowly.e. The latent period is longer because isotonic twitches only occur in slow(type I) muscle fibers.
Rigor mortis occurs following death because a. tropomyosin remains over the myosin binding sites of actin. b. myosin heads attach to actin and are not released due to lack of ATP. c. the myosin becomes misshapen. d. all of the Ca2+ remains within the sarcoplasmic reticulum.
Which of the following step(s) about the excitation of skeletal muscle is/are incorrect? 1. Acetylcholine is released and binds to motor end plate receptors 2. An action potential is created and moves down T-tubules 3. Calcium is released from the sarcoplasmic reticulum 4. Calcium ions bind to tropomyosin to shift troponin off the binding sites for cross-bridging 5. Myosin forms cross-bridges and binds with actin to pull it towards middle of sarcomere