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When Ca2+ ions are released from the sarcoplasmic reticulum, They combine with troponin, and this cause the tropomyosin threads to shift their position
Wiki User
∙ 13y ago
Wiki User
∙ 10y agoThe myosin binding sites on actin are exposed.
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What is the role of calcium ions in muscle contraction?
They bind to regulatory sites on troponin to remove contraction inhibition
What is needed besides calcium for contraction to occur?
An action potential. It is the nerve impulse that enters into sarcomeres from the sarcoplasmic reticulum and provides the energy for the calcium ions to briefly bind to the troponin on the actin myofilament to allow for contraction to occur by bringing the Z-lines closer together.
What happens with the many synaptic inputs on a cell body?
Ca ions bind to their binding sites that in turn allows Na ions to flood into the cell body and cause depolarization. this will continue down the cells axon until it bombardes the next cell with synaptic input
What is the mineral found in the bone?
Calcium
What does sarcoplasmic reticulum do?
The Sarcoplasmic Retiulum releases calcium ions that will cause troponin/tropomyosin complex to move. This exposes the binding sites on actin and allows the cross-bridges of myosin to bind to the actin binding sites.
What Steps in muscle contraction require calcium ions?
Calcium ions bind to troponin, changing troponin's shape
What occurs when intracellular calcium levels are high?
calcium ions bind to regulatory sites on troponin
What triggers the binding of myosin to actin?
Calcium ions bind to troponin and change its shape.
What is the role of calcium ions in muscle contraction?
They bind to regulatory sites on troponin to remove contraction inhibition
What specific event triggers the uncovering of the myosin site on actin?
Calcium ions bind to troponin and change its shape.
What bridge forms between Calcium ions?
Calcium bridges form between muscle cells. The calcium ions bind to troponin-tropomyosin molecules in the grooves of actin filaments and form crossbridges.
What unmasks troponin protein?
Ca 2+ ions released from the sarcomeres ER bind to troponin and force a conformational change that opens the way for myosin to bind to actin.
What mineral is needed to allow actin and myosin to interact?
In order for myosin to connect to actin's active sites, Ca ions must be released from storage in the sarcoplasmic reticulum into the sarcoplasm. A nerve impulse stimulates the release of Ca ions from the sarcoplasmic reticulum. Once the Ca ions are released into the sarcoplasm, they bind to troponin. Once they bind to troponin, troponin no longer is bound to tropomyosin. Tropomyosin is now no longer covering up actin's active sites, thus allowing myosin to attach to actin's active sites.
What is the role of the triad in muscle contraction?
Once a triad has been achieved, Calcium ions get released. Once they're released they bind to troponin, which helps begin muscle contraction.
What ions serve as a trigger for muscle contractions by removing the inhibition of the troponin molecule?
Calcium ions
Which mineral is key in muscle contraction due to it's affinity to troponin?
Calcium ions
Which molecules are involved with regulation of cross bridge attachment activity?
calcium ions, troponin, and tropomyosin
