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According to the figures, decreasing which of the following would create the greatest increase in charge stored per unit voltage on an axon membrane in its rest state?
A. Leakage channel resistance
B. Na+ channel resistance
C. Area of the membrane surfaces
D. Thickness of the membrane
Correct Answer
Explanation:
D. "Charge stored per unit voltage," Q / V, is the definition of capacitance, C. The equation for the capacitance of a parallel-plate capacitor is C = kϵ0A / d, where k is the dielectric constant, ϵ0 is a universal constant (the permittivity of free space), A is the area of each plate, and d is the distance between the plates. Of the choices given, only D, decreasing the thickness of the membrane (that is, decreasing d), would increase the capacitance, C.
ummmm
how do you work through this without knowing C = kϵ0A / d
i used V=Ed and C=Q/V
if you decrease d V decreases but alos according to C=Q/V decreasing v increases C
so how would you work through this without knowing C = kϵ0A / d
Na channel has a smaller resistance than leakage channels
also just want to double check is the voltage across the capacitor equal to 1/leakage + 1/Na = 1/R?? if so wouldn't decreasing the Na resistance have the greatest impact on increasing the voltage? im not that great w/ ratios and proportions but wouldn't the same magnitude of change have a greater impact on overall Na if it was applied to Na vs leakage channels?
A. Leakage channel resistance
B. Na+ channel resistance
C. Area of the membrane surfaces
D. Thickness of the membrane
Correct Answer
Explanation:
D. "Charge stored per unit voltage," Q / V, is the definition of capacitance, C. The equation for the capacitance of a parallel-plate capacitor is C = kϵ0A / d, where k is the dielectric constant, ϵ0 is a universal constant (the permittivity of free space), A is the area of each plate, and d is the distance between the plates. Of the choices given, only D, decreasing the thickness of the membrane (that is, decreasing d), would increase the capacitance, C.
ummmm
how do you work through this without knowing C = kϵ0A / d
i used V=Ed and C=Q/V
if you decrease d V decreases but alos according to C=Q/V decreasing v increases C
so how would you work through this without knowing C = kϵ0A / d
Na channel has a smaller resistance than leakage channels
also just want to double check is the voltage across the capacitor equal to 1/leakage + 1/Na = 1/R?? if so wouldn't decreasing the Na resistance have the greatest impact on increasing the voltage? im not that great w/ ratios and proportions but wouldn't the same magnitude of change have a greater impact on overall Na if it was applied to Na vs leakage channels?
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