When calcium ion binds to troponinQuestion 9Select one:a.active sites on the myosin are exposed.b.muscle relaxation occurs.c.myosin shortens.d.tropomyosin moves into the groove between the helical actin strands.e.actin heads will bind to myosin.
Question
When calcium ion binds to troponinQuestion 9Select one:a.active sites on the myosin are exposed.b.muscle relaxation occurs.c.myosin shortens.d.tropomyosin moves into the groove between the helical actin strands.e.actin heads will bind to myosin.
Solution
The correct answer is d. Tropomyosin moves into the groove between the helical actin strands.
Here's the step by step process:
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When a muscle cell is stimulated to contract, calcium ions are released from the sarcoplasmic reticulum, a specialized endoplasmic reticulum in muscle cells.
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These calcium ions bind to troponin, a protein that is associated with tropomyosin, another protein that is wound around actin strands in muscle cells.
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The binding of calcium to troponin causes a conformational change in the troponin-tropomyosin complex.
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This change causes tropomyosin to move into the groove between the helical actin strands.
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With tropomyosin out of the way, the active sites on actin are exposed.
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Myosin heads can now bind to these active sites, leading to muscle contraction.
Similar Questions
During contraction of a muscle, calcium ions bind to ______ which moves _______ out of the way. This now uncovers binding sites on the __________ myofilament. multiple choice 1troponin; tropomyosin; myosintroponin; tropomyosin; actintropomyosin; troponin; myosintropomyosin; troponin; actin 2. What molecules are attached to the myosin head from the previous cycle of movement? multiple choice 2ATP and phosphateADP and phosphateATP and calcium ionsADP and calcium ions 3. What is released in the process of cross-bridge formation? multiple choice 3ADPPhosphateATPCalcium ions 4. When the myosin head is moved, what is released (from the myosin head)? multiple choice 4ATPADPPhosphateCalcium ions 5. After the myosin head returns to its upright position, what occurs if calcium ions are still present? multiple choice 5Actin myofilaments move away from the M line.The entire sequence is repeated.Troponin blocks the binding sites on actin.Myosin heads will no longer bind to actin.
n order for muscle contraction to occur during exercise calcium must bind to which of the following proteins? troponin. tropomyosin. myosin. actin.
Uncovering binding sites for myosin on actin myofilaments involves troponin binding to ____________.Multiple ChoiceT tubulestropomyosinphosphatecalcium ions
The binding of Blank______ to the myosin head causes it to detach from G actin.Multiple choice question.calciumacetylcholineATP
Which of the following statements accurately describes the characteristics of human skeletal muscle contraction? A) Calcium ions bind to troponin, causing movement of tropomyosin and exposing the myosin binding sites on actin B) Calcium ions bind to troponin, causing movement of tropomyosin and exposing the actin binding sites for myosin C) Calcium ions bind to actin, causing movement of tropomyosin and exposing the myosin binding sites on actin D) Calcium ions bind to tropomyosin, causing movement of troponin and exposing the myosin binding sites for actin E) Calcium ions bind to tropomyosin, causing movement of troponin and exposing the actin binding sites for myosin
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