Podcast
Questions and Answers
What role do troponin and tropomyosin play in muscle contraction?
What role do troponin and tropomyosin play in muscle contraction?
- They regulate the exposure of myosin-binding sites on actin. (correct)
- They assist in the reuptake of calcium into the sarcoplasmic reticulum.
- They inhibit the action of calcium ions in the sarcoplasm.
- They facilitate the binding of actin to myosin.
Which statement about cross-bridge cycling is true?
Which statement about cross-bridge cycling is true?
- It only occurs during muscle relaxation phases.
- It is initiated by the release of calcium ions into the T tubules.
- It does not involve ATP directly.
- It occurs continuously as long as calcium ions are present. (correct)
What is the first step in the muscle contraction process after calcium ion release?
What is the first step in the muscle contraction process after calcium ion release?
- Cross-bridge formation between actin and myosin.
- Exposure of binding sites on actin. (correct)
- Binding of ATP to myosin heads.
- Hydrolysis of ATP into ADP and inorganic phosphate.
How does the action potential propagate through muscle fibers?
How does the action potential propagate through muscle fibers?
What triggers the opening of voltage-gated calcium channels in muscle contraction?
What triggers the opening of voltage-gated calcium channels in muscle contraction?
What directly results from the binding of acetylcholine to its receptor on the muscle membrane?
What directly results from the binding of acetylcholine to its receptor on the muscle membrane?
Which ion is crucial for initiating the contraction of skeletal muscle by facilitating cross-bridge cycling?
Which ion is crucial for initiating the contraction of skeletal muscle by facilitating cross-bridge cycling?
Which of the following correctly describes the role of sarcoplasmic reticulum in muscle contraction?
Which of the following correctly describes the role of sarcoplasmic reticulum in muscle contraction?
What role does calcium play in the muscle contraction process?
What role does calcium play in the muscle contraction process?
During the power stroke, what occurs to the myosin heads?
During the power stroke, what occurs to the myosin heads?
What happens to the tropomyosin during muscle contraction?
What happens to the tropomyosin during muscle contraction?
What initiates the process of cross-bridge cycling in muscle contraction?
What initiates the process of cross-bridge cycling in muscle contraction?
Which statement correctly describes the function of cross-bridges during contraction?
Which statement correctly describes the function of cross-bridges during contraction?
What occurs after the myosin heads perform a power stroke?
What occurs after the myosin heads perform a power stroke?
What change occurs in the myosin-actin interaction during contraction?
What change occurs in the myosin-actin interaction during contraction?
What is the result of myosin cross-bridges forming with actin during muscle contraction?
What is the result of myosin cross-bridges forming with actin during muscle contraction?
What is the primary role of the troponin-tropomyosin complex in muscle contraction?
What is the primary role of the troponin-tropomyosin complex in muscle contraction?
During the power stroke in cross-bridge cycling, which molecule is released from the myosin head?
During the power stroke in cross-bridge cycling, which molecule is released from the myosin head?
How does calcium influence the troponin-tropomyosin complex during muscle contraction?
How does calcium influence the troponin-tropomyosin complex during muscle contraction?
What effect does the attachment of ATP to the myosin head have on the cross-bridge cycling process?
What effect does the attachment of ATP to the myosin head have on the cross-bridge cycling process?
In the process of sliding filament theory, the thin filament slides toward which line in the sarcomere?
In the process of sliding filament theory, the thin filament slides toward which line in the sarcomere?
What is the consequence of calcium ion release from the sarcoplasmic reticulum?
What is the consequence of calcium ion release from the sarcoplasmic reticulum?
Which phase of cross-bridge cycling involves the myosin head pivoting and pulling the actin filament?
Which phase of cross-bridge cycling involves the myosin head pivoting and pulling the actin filament?
What role do ATP and ADP play in the cycling of myosin heads during muscle contraction?
What role do ATP and ADP play in the cycling of myosin heads during muscle contraction?
