QuestionSBA
QuestionChoice
Magnesium does not initiate the muscle contraction process, calcium ions do that. However, Magnesium ions are involved in various enzymatic reactions during muscle contraction, including the hydrolysis of ATP to release energy for the cross-bridge cycle.
10026693
d
Magnesium (Mg2+)
QuestionChoice
When a nerve impulse stimulates the muscle, it triggers the release of calcium ions from the sarcoplasmic reticulum. Calcium binds to troponin, a protein on the actin filament, exposing the myosin binding sites and allowing for cross-bridge formation.
10026690
a
Calcium (Ca2+)
QuestionChoice
Muscle contraction begins with the generation of an action potential, which travels along the sarcolemma. Sodium ions are crucial for initiating this action potential however they do not initiate the muscle contraction process, calcium ions do that.
10026691
b
Sodium (Na+)
QuestionChoice
Potassium ions do not initiate the muscle contraction process, calcium ions do that. However, after the depolarisation phase during the action potential, repolarisation is essential to reset the muscle cell's membrane potential for subsequent contractions. This involves the movement of potassium ions out of the cell, which helps restore the negative resting membrane potential. Repolarisation is crucial for muscle relaxation.
10026692
c
Potassium (K+)
QuestionChoice
Hydrogen ions do not initiate the muscle contraction process, calcium ions do that. Hydrogen ions can be produced during intense muscle contractions, such as during strenuous exercise leading to acidosis and muscle fatigue.
10026694
e
Hydrogen ions (H+)
Concept
Chapter
2693
5912
Sliding filament theory
Topic
152
Neuroscience
17736
Which ion is responsible for initiating muscle contraction?
a