Interpret the effect of hyperkalemia with reference to Goldman’s equation. a) What happens to rate of K+ diffusion at the MRP equilibrium with elevated extracellular [K+] (and unchanged intracellular [K+])? b) Since this diffusion rate determines the “permeability” of the cell to that K+ ion, what happens to PK+ as a result of this elevated extracellular K+? (Hint- it HAS changed.) c) Since PK+ has changed, and PNa+ is unchanged, what happens to the MRP as a result of this change in PK+? Explain with specific reference to Goldman’s equation but there is no need to cite or calculate any specific numbers, just generalize the result.

Interpret the effect of hyperkalemia with reference to Goldman’s equation. a) What happens to rate of K+ diffusion at the MRP equilibrium with elevated extracellular [K+] (and unchanged intracellular [K+])? b) Since this diffusion rate determines the “permeability” of the cell to that K+ ion, what happens to PK+ as a result of this elevated extracellular K+? (Hint- it HAS changed.) c) Since PK+ has changed, and PNa+ is unchanged, what happens to the MRP as a result of this change in PK+? Explain with specific reference to Goldman’s equation but there is no need to cite or calculate any specific numbers, just generalize the result.

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

Below find the structures for ibogaine and cocaine. Ibogaine and cocaine inhibit the dopamine active transporter (DAT). This transporter is a secondary active transporter, and depends on the primary active transporter Na+/K+ ATPase. Ibogaine had a Kι = 2 μM, and cocaine a Kι = 0.64 μM respectively. (a) Define secondary active transport. (b) Is ibogaine an effective treatment for cocaine based on DAT binding?
The resting membrane potential…A) Can be approximated using the Goldman-Hodgkin-Katz equation.B) Represents a difference in charges across the cell membrane, resulting mostly from the passive flow of Na+ions.C) Has no influence on the driving force that acts on different ions across the cell membrane.D) Is equally dependent on the concentration gradients of potassium and sodium across the cell membrane.E) Becomes hyperpolarized during an excitatory graded potential.
How much time would it take ATP to diffuse the following distances? (Use the equation for mean squared displacement in 1 dimension.) A. 1 µm (roughly the size of a bacterium) B. 6 µm (roughly the diameter of a T cell) C. 1 m (roughly the length of the axon of the sciatic nerve, which extends from the spinal cord to the big toe) D. Besides diffusion, what other mechanisms might a neuron use to transmit signals and transport molecules?
What two mechanisms are triggered by an increase in theosmolality of the extracellular fluid?
6) Consider the mechanism of net NaCl secretion across an epithelium shown below (in attachment) What provides the driving force for Cl- entry through the basolateral membrane into cell?
A. Assumed that the primary contributor to the absorbance of the samplewas due to the hemoglobins. Calculate how much red light the water in the sample absorbed.Explain whether or not ignoring water was a reasonable assumption. (use image down below to solve) B. There are several membrane-bound organelles in cells (e.g. nuclei, mitochondria,endoplasmic reticulum) that can also have ion channels in their membranes. Sketch anelectrical circuit model of a cell that expresses sodium, calcium, and chloride ion channels in itscellular membrane and calcium and chloride ion channels in its nuclear envelope membrane.
Glucose transport across cell membranes varies depending upon blood glucose levels. When glucose levels are high, glucose transport is accomplished via membrane transporters. When glucose concentrations are low, the transport of glucose across the membrane is dependent upon the sodium ion concentration. What types of transport is observed for glucose? A)simple diffusion at high [glucose], secondary active transport at low [glucose] B)facilitated diffusion at high [glucose], secondary active transport at low [glucose] C)simple diffusion at high [glucose], primary active transport at low [glucose] D)facilitated diffusion at high [glucose], primary active transport at low [glucose]
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?
Describe the contribution of each of the following to establishing and maintaining membrane potential: (a) the Na+K+ pump, (b) passive movement of K+ across the membrane, (c) passive movement of Na+ across the membrane, and (d) the large intracellular anions.
Which of the following arrangement based on the increasing order of motion is correct?a) Uncatalysed transverse motion, transverse diffusion catalyzed by flippase, uncatalysed lateral diffusionb) Uncatalysed lateral diffusion, uncatalysed transverse motion, transverse diffusion catalyzed by flippase,c) Uncatalysed transverse motion, uncatalysed lateral diffusion, transverse diffusion catalyzed by flippased) Transverse diffusion catalyzed by flippase, uncatalysed lateral diffusion, uncatalysed transverse motion,
Which of the following happens if the concentration of potassium in the extracellular fluid increases too much?A) Potassium would be taken up by the oligodendrocytes, so no net change in signaaaling would result. B) No signaling could occur. C) The Neuron would become hyperexcitable D) The sodium pumps would immediately fix the situation, so no net change in signaling would result.
Ouabain is a specific inhibitor of the active transport of sodium ions out of the cell and is therefore a valuable tool in studies of membrane transport mechanisms. Which of the following processes in your own body would you expect to be sensitive to inhibition by ouabain? Explain your answer in each case. a) Facilitated diffusion of glucose into a muscle cell b) Active transport of dietary phenylalanine across the intestinal mucosa c) Uptake of potassium ions by red blood cells d) Active uptake of lactose by the bacteria in your intestine