Question

matching vocabulary: which term matches which definition? some definitions will not be used!

1. membrane potential

a. require only the presence of an electrical impulse to open; allow sodium to pass in and potassium to pass out of the axon

1. action potential

a. require only the presence of an electrical impulse; allow sodium to pass out and potassium to pass into the axon

1. concentration gradient

c. a difference in the number of ions on the inside and outside of a cell which causes ions to flow through channels

1. equilibrium

d. require atp to open; pump 2 na+ in and 3 k+ out
e. require atp to open; pump 3 na+ out and 2 k+ in
f. sodium ions; there are more outside of a neuron’s axon than inside in resting conditions

1. voltage - gated channels

g. a difference in charge between the inside of a cell and the outside of a cell; measured in mv

1. sodium - potassium pumps

h. when the concentration of ions inside and outside the cell are similar so ions stop flowing freely
i. potassium ions; there are more inside of a neuron’s axon than outside in resting conditions

1. k+ ions

j. a nerve impulse that travels down the axon; changes the charge of the axon from negative to positive

1. na+ ions

k. a nerve impulse that travels down the axon; changes the charge of the axon from positive to negative
neuron anatomy: label the neuron below with the following structures: axon, axon terminals, dendrites
draw an arrow the direction that the action potential travels down the neuron

Explanation:

1. Membrane potential is the charge difference across a cell membrane, measured in mV.
2. Action potential is the nerve impulse that travels down the axon, flipping the axon's charge from negative to positive.
3. Concentration gradient is the difference in ion counts inside/outside a cell, driving ion flow.
4. Equilibrium is when ion concentration differences balance, stopping free ion flow.
5. Voltage-gated channels only open with an electrical impulse, letting sodium enter the axon.
6. Sodium-potassium pumps use ATP to move 3 Na⁺ out and 2 K⁺ in.
7. K⁺ ions are more concentrated inside a resting neuron's axon.
8. Na⁺ ions are more concentrated outside a resting neuron's axon.

Answer:

1. G. A difference in charge between the inside of a cell and the outside of a cell; measured in mV
2. J. A nerve impulse that travels down the axon; changes the charge of the axon from negative to positive
3. C. A difference in the number of ions on the inside and outside of a cell which causes ions to flow through channels
4. H. When the concentration of ions inside and outside the cell are similar so ions stop flowing freely
5. A. Require only the presence of an electrical impulse to open; allow sodium to pass in and potassium to pass out of the axon
6. D. Require ATP to open; pump 2 Na+ in and 3 K+ out
7. I. Potassium ions; there are more INSIDE of a neuron's axon than outside in resting conditions
8. F. Sodium ions; there are more OUTSIDE of a neuron's axon than inside in resting conditions