Question

In: Chemistry

Calculate the Vm of a cell that is permeable to sodium and potassium at 22 degrees...

Calculate the Vm of a cell that is permeable to sodium and potassium at 22 degrees Celsius. What is the effect of the temperature on the Vm of the cell? Hint need to look up information on the Nernst equation in order to solve this.​

Pk = 100, PNa = 5, PCl = 10, PCa = 1

Extracellular conc. of potassium: 5 mM

Extracellular conc. of sodium: 150 mM

Intracellular conc. of potassium: 100 mM

Intracellular conc. of sodium: 15 mM

NOTE THAT THE CELL IS PERMEABLE TO SODIUM & POTASSIUM​. Also, would you or would you not take the ratio for the sodium-potassium pump into consideration?

Solutions

Expert Solution

Vm is the equilibrium membrane potential is exactly equal and opposite to the diffusive forces of ions ,so that no net flow of ions occurs in and out of the cell membrane.This value depends only on the concentration of ions inside and outside the cell membrane.The ratio of sodium and potassium pump is taken into consideration in Vm calculations.

goldmann-hodgkin-katz equation to calculate Vm:

Vm=RT/F ln( (PK [K]out+PNa [Na]out +PCl[Cl]in+PCa[Ca]out)/(PK [K]in+PNa [Na]in +PCl[Cl]out+PCa[Ca]in))

where R=universal gas constant=8.314 J/K.mol

T=temperature =22+273=295K

F=faraday's constant =96485 C/mol

Pi represents the permeability of ion i

[ION}out =concentration of ion outside

[ION]in =concentration of ion inside

Vm=(8.314J/Kmol)*295K/ (96485 C/mol) ln( (100 *5mM+5* 150mM )/(100 *100mM+5* 15mM)) [As Cl- is not actively pumped ,it hardly affects Vm )

Vm=0.0254V ln (1250mM/10075mM)=-0.053V

Vm=-0.053V


Related Solutions

erve impulse moves along a neuron as A. sodium moves into the cell and potassium moves...
erve impulse moves along a neuron as A. sodium moves into the cell and potassium moves out of the cell. B. sodium binds to potassium. C. sodium and potassium are pulled apart. D. acetylcholine moves along the nerve fiber. E. calcium exits the dendrites. 1 points Question 57 How might climate change effect the reproductive success of organisms? A. Changes in the length of seasons. B. Changes in seasonal temperature. C. There will not be much of an effect. D....
4. The movement of sodium and potassium ions via sodium channel and potassium channel proteins is...
4. The movement of sodium and potassium ions via sodium channel and potassium channel proteins is A. Active Process B. Passive process C. Both D. None of the above 5. The Na/K voltage gated channel protein uses __________ to move sodium and potassium across the plasma membrane. 6. The ion, which conduct electricity, is: a. A charged atom b. a charged molecule c. Both A and B are correct d. none of these are correct 7. In a resting membrane...
What is osmoregulation and why don't plants need sodium-potassium pump to regulate cell osmolarity?
What is osmoregulation and why don't plants need sodium-potassium pump to regulate cell osmolarity?
A cell membrane at 37°C is found to be permeable to Ca2+ but not to anions,...
A cell membrane at 37°C is found to be permeable to Ca2+ but not to anions, and analysis shows the inside concentration to be 0.100 M and the outside concentration to be 0.001 M in Ca2+. a) What potential difference in volts would have to exist across the membrane for Ca2+ to be in equilibrium at the stated concentrations? Assume that activity coefficients are equal to 1. Give the sign of the potential inside with respect to the outside. b)...
Diagram a mechanism of action for the sodium potassium ATPase.
Diagram a mechanism of action for the sodium potassium ATPase.
How does hydration of sodium and potassium play an important role in the selectivity of the potassium channel ?
How does hydration of sodium and potassium play an important role in the selectivity of the potassium channel ?
The cell membranes of mammalian red blood cells are permeable to urea. If red blood cells...
The cell membranes of mammalian red blood cells are permeable to urea. If red blood cells are dropped into a solution of urea that is identical in osmotic pressure (isosmotic) to the cytoplasm of the cells, although the cells do not swell and burst as quickly as when they are dropped simply into pure water, they eventually swell and burst. Explain. Also discuss how you would design a solution into which red cells could be placed without ever swelling. (Hint:...
High and low symptoms: potassium, calcium, phosphate, magnesium, sodium ?
High and low symptoms: potassium, calcium, phosphate, magnesium, sodium ?
Digitalis affects what protein? A) potassium ion channels b)ligand gated channels c)sodium/potassium ATPase d)calcium ATPase e)sodium...
Digitalis affects what protein? A) potassium ion channels b)ligand gated channels c)sodium/potassium ATPase d)calcium ATPase e)sodium ion channels
movement of potassium ions out of the cell causes the membrane to
movement of potassium ions out of the cell causes the membrane to
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT