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1. A resting neuron has a higher concentration of K+ on the inside of the cell and a higher concentration of Na+ on the outside of the cell. The net charge on the inside of the cell is negative.
2. A neuron transmits a signal by generating an action potential, which is a wave of positive charge generated when sodium ions rush into the cell.
3. e-b-d-c-a-f
4. A neuron actively transports 3 Na+ ions out for every 2 K+ ions brought in. This creates a net movement of positive charges out of the cell. The inside of the neuron also has large proteins that carry an overall negative charge, further contributing to the negative interior.
5. g-f-b-d-a-e-c
6. When an action potential reaches the end of the presynaptic neuron, it must rely on the chemicals called neurotransmitters to cross the space between adjacent neurons (the synapse). Once the chemicals bind to the postsynaptic neuron, sodium channels will open and the action potential will continue.
7. d. The neurotransmitters are contained within vesicles, and for the chemical to be released into the synapse, the vesicles need to migrate toward (and fuse with) the membrane at the synaptic terminal.