Podcast
Questions and Answers
What happens when Ca2+ binds to troponin in muscle contraction?
What happens when Ca2+ binds to troponin in muscle contraction?
- Voltage-sensitive tubule proteins return to their original shape.
- Troponin changes shape, exposing myosin binding sites on the thin filaments. (correct)
- Myosin-actin interaction is inhibited.
- Tropomyosin blocks active sites on actin.
What initiates the cross bridge cycling in muscle contraction?
What initiates the cross bridge cycling in muscle contraction?
- Tropomyosin blocking active sites.
- Myosin binding to actin. (correct)
- Ca2+ being pumped back into the SR.
- Voltage-sensitive tubule proteins changing shape.
What occurs when the muscle action potential ceases in terms of calcium levels?
What occurs when the muscle action potential ceases in terms of calcium levels?
- Ca2+ is released from the SR to the cytosol. (correct)
- Ca2+ release channels of the SR remain open.
- Ca2+ levels in the sarcoplasm rise.
- Ca2+ is continually pumped back into the sarcoplasm.
What happens when Ca2+ levels are low in muscle contraction?
What happens when Ca2+ levels are low in muscle contraction?
What leads to relaxation in muscle fibers during contraction?
What leads to relaxation in muscle fibers during contraction?
What occurs each time an action potential arrives at the neuromuscular junction?
What occurs each time an action potential arrives at the neuromuscular junction?
What happens when Ca2+ is absent in muscle contraction?
What happens when Ca2+ is absent in muscle contraction?
During excitation-contraction (E-C) coupling, where does the action potential propagate?
During excitation-contraction (E-C) coupling, where does the action potential propagate?
Which protein blocks active sites on actin in muscle contraction?
Which protein blocks active sites on actin in muscle contraction?
What leads to the sliding of myofilaments during muscle contraction?
What leads to the sliding of myofilaments during muscle contraction?
In which step of excitation-contraction (E-C) coupling are calcium ions released?
In which step of excitation-contraction (E-C) coupling are calcium ions released?
What happens to myosin-actin interaction if tropomyosin is blocking the active sites?
What happens to myosin-actin interaction if tropomyosin is blocking the active sites?
What is the role of ATP in muscle contraction?
What is the role of ATP in muscle contraction?
How does higher intracellular calcium concentration contribute to muscle contraction?
How does higher intracellular calcium concentration contribute to muscle contraction?
What happens during the working (power) stroke in the cross bridge cycle?
What happens during the working (power) stroke in the cross bridge cycle?
What is the function of tropomyosin in muscle contraction?
What is the function of tropomyosin in muscle contraction?
What causes cross bridge detachment in the sarcomere?
What causes cross bridge detachment in the sarcomere?
In the context of muscle contraction, what does troponin do?
In the context of muscle contraction, what does troponin do?
