Question

During an action potential,what is the role of calcium?

• A. The calcium binds to the myosin molecule in the sarcomere.
• B. The calcium causes the release of acetylcholine in the neuron into the synaptic cleft.
• C. There is no role for calcium during action potential.
• D. The calcium breaks down ATP to ADP and inorganic phosphate.

Answer 1

The correct option is B

The calcium causes the release of acetylcholine in the neuron into the synaptic cleft.

Nerve impulses also known as action potentials travel from the brain or the spinal cord to trigger the contraction of skeletal muscles. Muscles require innervation to function(Neuromuscular junction). Synaptic transmission at the neuromuscular junction begins when an action potential reaches the presynaptic terminal of a motor neuron, which activates voltage dependent calcium channels to allow calcium ions to enter the neuron. Calcium ions bind to sensor proteins on synaptic vesicles, triggering vesicle fusion with the cell membrane and subsequent acetylcholine release from the motor neuron into the synaptic cleft.