PSL 425 Final Exam Question
The resting membrane potential is mainly determined by:
a. The sodium gradient
b. The chloride gradient
c. The potassium gradient
d. The calcium gradient correct answers The potassium gradient
The net outward flow of chloride would best be described as a:
a. Equilibrium Current
b. Inward current
c. Outward current
d. Positive Current correct answers Inward current
What does the Nernst Equation predict for any concentration gradient of a particular ion
across a membrane?
a. The resting membrane potential
b. The permeability of the ion
c. The equilibrium membrane potential
d. The charge of the ion correct answers The equilibrium membrane potential
When substance is uncharged, as in the case of glucose, when can equilibrium occur?
a. Only when the concentration is equal on the two sides of the membrane
b. Equilibrium can never occur in this instance
c. Only when the voltage different is zero
d. Only when the external concentration matches the internal concentration of
potassium correct answers Only when the concentration is equal on the two sides of
the membrane
Which answer correctly orders the Nernst potentials of a cell at 37 C for potassium,
sodium, calcium, and chloride from depolarized to hyperpolarized?
a. Ca2+ > Na+ > Cl- > K+
b. K+ > Na+ > Ca2+ > Cl-
c. Na+ > Ca2+ > Cl- > K+
d. K+ > Ca2+ > Cl- > Na+ correct answers Ca2+ > Na+ > Cl- > K+
What is the name for the movement of a single ion species through the membrane?
a. Charge
, b. Resistance
c. Voltage
d. Current correct answers Current
What directions are the chemical driving force (CDF) and the electrical driving force
(EDF) for a hypothetical positive ion (X+) given values below:Extracellular concentration
[X-] = 15 mMIntracellular concentration [X-] = 100 mMMembrane Voltage Vm = -60 mV
a. CDF in & EDF out
b. CDF in & EDF in
c. CDF out & EDF in
d. CDF out & EDF out correct answers CDF out & EDF in
What would happen to the equilibrium potential of potassium if the extracellular
potassium concentration decreased?
a. Repolarize
b. Depolarize
c. Hyperpolarize
d. Nothing correct answers Hyperpolarize
If neither the chemical nor the electrical term in the electrochemical potential energy
difference equation are zero, when can equilibrium occur?
a. When the chemical term is positive and the electrical term is negative
b. When the two terms are equal but of opposite sign
c. Equilibrium can never occur
d. When the chemical term is negative and the electrical term is positive correct
answers When the two terms are equal but of opposite sign
The net inward flow of potassium would best be described as a:
a. Equilibrium current
b. Positive Current
c. Outward current
d. Negative Current correct answers Negative current
If the membrane is permeable to multiple monovalent ions and only these ions, the total
ionic current would be the _______ of the individual ionic currents
a. Product
b. Sum of the reciprocal
c. Sum
d. Product of the reciprocal correct answers sum
The resting membrane potential is mainly determined by:
a. The sodium gradient
b. The chloride gradient
c. The potassium gradient
d. The calcium gradient correct answers The potassium gradient
The net outward flow of chloride would best be described as a:
a. Equilibrium Current
b. Inward current
c. Outward current
d. Positive Current correct answers Inward current
What does the Nernst Equation predict for any concentration gradient of a particular ion
across a membrane?
a. The resting membrane potential
b. The permeability of the ion
c. The equilibrium membrane potential
d. The charge of the ion correct answers The equilibrium membrane potential
When substance is uncharged, as in the case of glucose, when can equilibrium occur?
a. Only when the concentration is equal on the two sides of the membrane
b. Equilibrium can never occur in this instance
c. Only when the voltage different is zero
d. Only when the external concentration matches the internal concentration of
potassium correct answers Only when the concentration is equal on the two sides of
the membrane
Which answer correctly orders the Nernst potentials of a cell at 37 C for potassium,
sodium, calcium, and chloride from depolarized to hyperpolarized?
a. Ca2+ > Na+ > Cl- > K+
b. K+ > Na+ > Ca2+ > Cl-
c. Na+ > Ca2+ > Cl- > K+
d. K+ > Ca2+ > Cl- > Na+ correct answers Ca2+ > Na+ > Cl- > K+
What is the name for the movement of a single ion species through the membrane?
a. Charge
, b. Resistance
c. Voltage
d. Current correct answers Current
What directions are the chemical driving force (CDF) and the electrical driving force
(EDF) for a hypothetical positive ion (X+) given values below:Extracellular concentration
[X-] = 15 mMIntracellular concentration [X-] = 100 mMMembrane Voltage Vm = -60 mV
a. CDF in & EDF out
b. CDF in & EDF in
c. CDF out & EDF in
d. CDF out & EDF out correct answers CDF out & EDF in
What would happen to the equilibrium potential of potassium if the extracellular
potassium concentration decreased?
a. Repolarize
b. Depolarize
c. Hyperpolarize
d. Nothing correct answers Hyperpolarize
If neither the chemical nor the electrical term in the electrochemical potential energy
difference equation are zero, when can equilibrium occur?
a. When the chemical term is positive and the electrical term is negative
b. When the two terms are equal but of opposite sign
c. Equilibrium can never occur
d. When the chemical term is negative and the electrical term is positive correct
answers When the two terms are equal but of opposite sign
The net inward flow of potassium would best be described as a:
a. Equilibrium current
b. Positive Current
c. Outward current
d. Negative Current correct answers Negative current
If the membrane is permeable to multiple monovalent ions and only these ions, the total
ionic current would be the _______ of the individual ionic currents
a. Product
b. Sum of the reciprocal
c. Sum
d. Product of the reciprocal correct answers sum
