f all of the calcium within a muscle fiber was removed (but ATP was still present), which of the following could still occur?Check All That ApplyThe heads of the myosin myofilaments bind to G actin to form cross-bridges.The heads of the myosin myofilaments bind to G actin to form cross-bridges.An action potential that reaches the end of an axon results in the release of acetylcholine.An action potential that reaches the end of an axon results in the release of acetylcholine.The troponin molecules of thin filaments change shape, causing tropomyosin to move and expose myosin binding sites.The troponin molecules of thin filaments change shape, causing tropomyosin to move and expose myosin binding sites.Myosin heads return to their resting position as the recovery stroke occurs.
Question
f all of the calcium within a muscle fiber was removed (but ATP was still present), which of the following could still occur?Check All That ApplyThe heads of the myosin myofilaments bind to G actin to form cross-bridges.The heads of the myosin myofilaments bind to G actin to form cross-bridges.An action potential that reaches the end of an axon results in the release of acetylcholine.An action potential that reaches the end of an axon results in the release of acetylcholine.The troponin molecules of thin filaments change shape, causing tropomyosin to move and expose myosin binding sites.The troponin molecules of thin filaments change shape, causing tropomyosin to move and expose myosin binding sites.Myosin heads return to their resting position as the recovery stroke occurs.
Solution
If all of the calcium within a muscle fiber was removed but ATP was still present, the following could still occur:
- An action potential that reaches the end of an axon results in the release of acetylcholine. This is because the release of acetylcholine is a process that is triggered by an action potential reaching the end of an axon, and it does not directly depend on the presence of calcium within the muscle fiber.
However, the following would not be able to occur:
-
The heads of the myosin myofilaments bind to G actin to form cross-bridges. This process requires calcium to bind to troponin, which then causes tropomyosin to move and expose the myosin binding sites on actin.
-
The troponin molecules of thin filaments change shape, causing tropomyosin to move and expose myosin binding sites. This process is directly dependent on the presence of calcium. When calcium binds to troponin, it causes a conformational change that moves tropomyosin and exposes the myosin binding sites.
-
Myosin heads return to their resting position as the recovery stroke occurs. This process, known as the recovery stroke, is dependent on the presence of ATP, but it also requires calcium for the initial binding of myosin to actin, which precedes the recovery stroke. Without calcium, the myosin heads would not be able to bind to actin and the recovery stroke would not occur.
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.
The break down of ATP by myosin-ATPase leads to Blank______.Multiple choice question.the cocking of the myosin headtransformation of troponinrecoil of the elastic fibersshortening of actin chains
The binding of Blank______ to the myosin head causes it to detach from G actin.Multiple choice question.calciumacetylcholineATP
Which of the following stores calcium within a muscle fiber?Multiple choice question.MyofibrilSarcolemmaSarcoplasmic reticulumTransverse tubule
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.