The role of calcium ion at chemical synapses is to
A)Depolarize the axon terminal of the presynaptic cell
B)Bind to neurotransmitter receptors on the postsynaptic cell
C)Cause fusion of synaptic vesicles with the plasma membrane of the axon terminal
D)Interfere with IPSPs in the postsynaptic cell
E)All of the choices are correct

Question

Quizplus · Accepted Answer

Calcium ion plays a crucial role in chemical synapses by causing the fusion of synaptic vesicles with the plasma membrane of the axon terminal, enabling the release of neurotransmitters into the synaptic cleft. This process is called synaptic exocytosis and is triggered by the influx of calcium ions into the presynaptic cell. The other choices are not accurate: A is incorrect because depolarization of the axon terminal is not the role of calcium ions, rather it is the result of the entry of calcium ions; B is incorrect because binding to neurotransmitter receptors on postsynaptic cells is the role of the neurotransmitter, not calcium ions; D is incorrect because calcium ions do not interfere with IPSPs (inhibitory postsynaptic potentials).

The Role of Calcium Ion at Chemical Synapses Is to