PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
What is a time constant?
The magnitude of a signal when it falls to 37% of its initial value
The time required for a signal to fall to 63% of its initial value
The magnitude of a signal when it falls to 63% of its initial value
The time required for a signal to fall to 37% of its initial value -
ANSWERS-The time required for a signal to fall to 37% of its initial
value
What is a siemens?
A unit of resistance
A unit of capacitance
A unit of charge
A unit of conductance - ANSWERS-A unit of conductance
What direction is the current when the membrane potential is more
positive than the equilibrium potential?
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PAGE
1
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
Outward
Inward
No current - ANSWERS-Outward
The opening and closing process of ion channels is called __________.
Shunting
Unitary movement
Capacitance
Gating - ANSWERS-Gating
What is the essential function of an ion channel?
To store charge across the membrane
To produce the concentration gradient of ions across the membrane
To facilitate the passive flow of ions across the membrane
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PAGE
2
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
All of the above - ANSWERS-To facilitate the passive flow of ions
across the membrane
What element of the cell membrane circuit model can the equilibrium
potential of an ion be considered?
Inductor
Electromotive force
Variable resistor
Capacitor - ANSWERS-Electromotive Force
What is an ionic current called that is due to the activity of a large
population of channels sampled from a whole cell?
Unitary current
Capacitative current
Single channel current
Macroscopic current - ANSWERS-Macroscopic Current
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PAGE
3
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
A ligand-gated channel is activated by __________.
an agonist
an intracellular messenger
a membrane voltage
'all of the above - ANSWERS-An agonist
What is capacitative current in a circuit model?
Movement of charge through ion pumps
Movement of charge through ion channels
Movement of charge across the capacitor
Movement of charge onto or off the capacitor - ANSWERS-Movement
of charge onto or off the capacitor
What is a factor that can distinguish an ion channel class based on
electrophysiology?
END OF
PAGE
4
QUESTIONS AND
ANSWERS 2026 - 2027
What is a time constant?
The magnitude of a signal when it falls to 37% of its initial value
The time required for a signal to fall to 63% of its initial value
The magnitude of a signal when it falls to 63% of its initial value
The time required for a signal to fall to 37% of its initial value -
ANSWERS-The time required for a signal to fall to 37% of its initial
value
What is a siemens?
A unit of resistance
A unit of capacitance
A unit of charge
A unit of conductance - ANSWERS-A unit of conductance
What direction is the current when the membrane potential is more
positive than the equilibrium potential?
END OF
PAGE
1
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
Outward
Inward
No current - ANSWERS-Outward
The opening and closing process of ion channels is called __________.
Shunting
Unitary movement
Capacitance
Gating - ANSWERS-Gating
What is the essential function of an ion channel?
To store charge across the membrane
To produce the concentration gradient of ions across the membrane
To facilitate the passive flow of ions across the membrane
END OF
PAGE
2
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
All of the above - ANSWERS-To facilitate the passive flow of ions
across the membrane
What element of the cell membrane circuit model can the equilibrium
potential of an ion be considered?
Inductor
Electromotive force
Variable resistor
Capacitor - ANSWERS-Electromotive Force
What is an ionic current called that is due to the activity of a large
population of channels sampled from a whole cell?
Unitary current
Capacitative current
Single channel current
Macroscopic current - ANSWERS-Macroscopic Current
END OF
PAGE
3
, PSL 425 FINAL EXAM LATEST
QUESTIONS AND
ANSWERS 2026 - 2027
A ligand-gated channel is activated by __________.
an agonist
an intracellular messenger
a membrane voltage
'all of the above - ANSWERS-An agonist
What is capacitative current in a circuit model?
Movement of charge through ion pumps
Movement of charge through ion channels
Movement of charge across the capacitor
Movement of charge onto or off the capacitor - ANSWERS-Movement
of charge onto or off the capacitor
What is a factor that can distinguish an ion channel class based on
electrophysiology?
END OF
PAGE
4
