The distribution of Na* ions across a typical biological membrane is 10 mmol/dm³ nside the cell, and 140 mmol/dm³ outside the cell. At equilibrium, the concentrations across the membrane are equal. What is the Gibbs energy difference across the membrane at 37°C? The stated difference in concentration MUST be maintained by coupling to reactions that have at least your calculated difference of Gibbs energy. Ans: 6.8 kJ/mol

The distribution of Na* ions across a typical biological membrane is 10 mmol/dm³ nside the cell, and 140 mmol/dm³ outside the cell. At equilibrium, the concentrations across the membrane are equal. What is the Gibbs energy difference across the membrane at 37°C? The stated difference in concentration MUST be maintained by coupling to reactions that have at least your calculated difference of Gibbs energy. Ans: 6.8 kJ/mol

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter3: The Plasma Membrane And Membrane Potential

Section: Chapter Questions

Problem 2SQE: One of the important uses of the Nernst equation is in describing the flow of ions across plasma...

See similar textbooks

Similar questions

One of the important uses of the Nernst equation is in describing the flow of ions across plasma membranes. Ions move under the influence of two forces: the concentration gradient (given in electrical units by the Nernst equation) and the electrical gradient (given by the membrane voltage). This is summarized by Ohms law: Ix=Gx(VmEx) which describes the movement of ion x across the membrane. I is the current in amperes (A); G is the conductance, a measure of the permeability of x, in Siemens (S), which is I/V;Vm is the membrane voltage; and Ex is the equilibrium potential of ion x. Not only does this equation tell how large the current is, but it also tells what direction the current is flowing. By convention, a negative value of the current represents either a positive ion entering the cell or a negative ion leaving the cell. The opposite is true of a positive value of the current. a. Using the following information, calculate the magnitude of Na [ Na+ ]0=145mM,[ Na+ ]i=15mM,Gna+=1nS,Vm=70mV b. Is Na+ entering or leaving the cell? c. Is Na+ moving with or against the concentration gradient? Is it moving with or against the electrical gradient?
What would be the free-energy change generated by the import of one mole of Na+ from a concentration of 10 mM to 150 mM with a membrane potential of −25 mV at 37°C? Give your answer without units and to one decimal place. F = 96.5 kJ/V•mol
The difference in chemical potential of a particular substance between two regions of a system is −8.3 kJ mol−1. By how much does the Gibbs energy change when 0.15 mmol of that substance is transferred from one region to the other?
Given that the relative molecular mass of potassium chloride (KCl) is 74.5513 g mol-1, calculate the concentration of potassium chloride solution which will be iso-osmotic with tears (305 mOsM). State your answer in both molar concentration (mol/L) and in percentage (g/100 mL). Please answer very soon will give rating surely
Calculate the equilibrium membrane potentials to be expected across a membrane at 37 ∘C, with a NaCl concentration of 0.50 M on the "right side" and 0.08 M on the "left side", given the following conditions. In each case, state which side is (+) and which is (−). Membrane equally permeable to both ions.
V=62 log 10 (C0/Ci ) for a positive ion at 37 degrees Celsius. What is theoretical ratio of solution ion across the membrane when the resting membrane potential is 124 mV?
You have a semi permeable membrane with a membrane potential of -90mV. You also have two ions that are both permeable to the membrane, Na and Cl. Na has a concentration of 10mM inside the membrane and 120mM outside the membrane. Cl has a concentration of 1.5mM inside the membrane and 77.5mM outside the membrane. Use the nernst equation to calculate the electrochemical equilibrium of both ions, and show in which direction the netflux would be for each ion.
Consider a suspension of particles (isoelectric point is at pH 6) in water at pH 2 and a NaCl concentration of 0.001 M. Describe how the strength of repulsion varies with the following changes, assuming all other conditions remain constant. Give a description (more than just increase or decrease) in terms of the effect on the double layer thickness and the zeta potential. (a) Change from 0.001 M NaCl to 0.1 M NaCl, (b) Change from pH = 2 to pH = 5.
The equilibrium potential for a given ion (Eion) is a theoretical value. For a given concentration gradient of an ion, the equilibrium potential is the charge inside the cell required to hold an ion at that concentration. That is, it is the charge required to perfectly oppose the drive of the ion to move down its concentration gradient. So, if the concentration of Nat is higher outside the cell than inside, its equilibrium potential (ENa) must be I and if we add more sodium to the extracellular fluid, then ENa will II.
Calculate the equilibrium membrane potentials to be expected across a membrane at 37 ∘C, with a NaCl concentration of 0.50M on the "right side" and 0.08 M on the "left side", given the following conditions. In each case, state which side is (+) and which is (−). Membrane permeable only to Cl−.
Gout is caused by an error in metabolism that leads to abuildup of uric acid in body fluids, which is deposited as slightlysoluble sodium urate (C₅H₃N₄O₃Na) in the joints. If the extra-cellular [Na⁺] is 0.15 Mand the solubility of sodium urate is0.085 g/100. mL, what is the minimum urate ion concentration(abbreviated [Ur⁻]) that will cause a deposit of sodium urate?
What is the molar oconcentration of 30g KCl and 30g of CaCl2 added to 50 dL of DI water? a.) what is the molar concerntration of Ca2+ b.) what is the molar concentration of K+ c.) what is the molar concentration of Cl- d.) what is the osmolarity of this solution? e.) what is the tonicity of this solution?