when calculating the Resting membrance potential using the goldman equation it is usally out, out , in / in, in, out. the cl- is switched so does that mean that when writing the in and out cellular concentartion should we still add negative sign in front of the value or since it is flipped we shouldnt?

when calculating the Resting membrance potential using the goldman equation it is usally out, out , in / in, in, out. the cl- is switched so does that mean that when writing the in and out cellular concentartion should we still add negative sign in front of the value or since it is flipped we shouldnt?

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

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter4: Principles Of Neural And Hormonal Communication

Section: Chapter Questions

Problem 3SQE

See similar textbooks

Similar questions

The typical distribution of K+ and Na+ ions inside and outside the cell is: [K+]in = 150 mM; [K+]out = 5 mM; [Na+]in = 10 mM; [Na+]out = 150 mM What are reversal potentials for Na+ and K+ at 25oC ? What should be the ratios of PNa/PK at (i) rest (-60 mV) and (ii) during the action potential (+20 mV) to generate a spike from -60 to +20 mV. Use the short form of Goldman equation.
What is the intracellular voltage for Cl- if the intracellular concentration was 5 mM and the extracellular concentration was 130 mM. Write the voltage as a number in mV inside the cell relative to that outside, eg. -72 or + 90. Question 2. What is the intracellular voltage for Ca++ if the intracellular concentration was 0.0008 mM and the extracellular concentration was 0.6 mM. Write the voltage as a number in mV inside the cell relative to that outside, eg. -72 or +90. Round to the nearest milli Volt.
You are recording from a cell with a resting membrane potential of -65 mV. You inject 100 pA of current, resulting 58.7 mV. What is the value of tau? With this in mind, what is the capacitance of the cell? Please provide relevant equations to illustrate your thought process. When you terminate the current injection, how long do you expect for it to take for the cell to repolarize to -63 mV?
Myasthenia gravis is a disease that leads to a marked decrease in the number of acetylcholine (Ach) receptors at the neuromuscular junction. As a result, suppose only about 200 (instead of 2000) Ach receptor-channels are opened by each quantum of Ach. The Ach-gated channels that survive operate normally and each cause a depolarization of about 0.25 x 10-3 mV when open. The function of the presynaptic terminal is normal and an action potential will cause the release of 100 quanta of neurotransmitter. For a patient with myasthenia gravis, what would be the magnitude of the depolarization (in mV) associated with opening of one Ach-gated channel? a.) 0.25x10^-2 mv b.) 0.25x10^-3 mv c.) 0.25x10^-4 mv d.) 0.5x10^-1 mv e.) 0.5 mv
Myasthenia gravis is a disease that leads to a marked decrease in the number of acetylcholine (Ach) receptors at the neuromuscular junction. As a result, suppose only about 200 (instead of 2000) Ach receptor-channels are opened by each quantum of Ach. The Ach-gated channels that survive operate normally and each cause a depolarization of about 0.25 x 10-3 mV when open. The function of the presynaptic terminal is normal and an action potential will cause the release of 100 quanta of neurotransmitter. Part a.) For a patient with myasthenia gravis, what would be the size (in mV) of a miniature excitatory post-synaptic potential (or that associated with one quantum of Ach)? a.) 0.05 mv b.) 0.25x10-4 mv c.) 0.25x10-3 mv d.) 0.5x10-3 mv e.) 0.5 mv Part b.) For a patient with myasthenia gravis, what would be the size (in mV) of the full excitatory post synaptic potential consequent to the entry of an action potential into the presynaptic terminal of the neuromuscular junction? a.) 70 mv…
The top panel (a) of this figure shows the graded potential change (far right, upper, electrical trace) that results from ligand binding to the ligand gated Na+ channel. The bottom panel of this figure (b) shows a graded potential change (far right, lower, electrical trace) that results from ligand binding to a ligand gated Cl- channel. From this trace you know (Vm = -70 mV) 1. ECl- is -70 mV 2. ECl- is more negative than -70 mV (i.e., -80 mV) 3. ECl- is more positive than -70 mV (i.e., -60 mV)
Calculate the free energy of transport for the movement of potassium by the sodium/potassium pump under normal physiological conditions: 4 mM serum potassium, 135 mM intracellular potassium, 37.1 °C, and resting potential -82 mV. Express your answer in kJ/mol. Show all work. Calculate the free energy of transport for the movement of potassium by the sodium/potassium pump under disturbed conditions of 2 mM serum potassium. Assume all other parameters remain the same. Express your answer in kJ/mol. Show all work. What factors could limit the continued action of the sodium/potassium pump when only 2 mM potassium is present in the blood plasma? Note that under normal physiological conditions, the cell interior contains 11 mM sodium and the blood contains 140 mM sodium.
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?
The following concentrations of Na+ and K+ ions: [Na+]o = 120 mM, [Na+]i = 6 mM,[K+]o = 2 mM, and [K+]i = 150 mM. Assuming that the further at the peak of the action potential, PK: PNa is 1 : 12. Calculate (Vm) at the peak of the action potential
Patch clamp recording of a single ion channel yields the following results: Holding Potential (mV) Measured Current (pA) -100 -1.0 -50 0.0 0 +1.0 +50 +2.0 +100 +3.0 part a.) Calculate the membrane potential at the instant when a neuron has the following relative permeabilities: PK+ = 1.0, PNa+ = 1.0, PCl- = 1.0. Use the ionic concentration values in the picture included. a.) -12 mv b.) -35mv c.) -60 mv d.) +20 mv e.) 0 mv part b.) What would be the equilibrium potential for K+ in neurons under such circumstances? a.) -11 mv b.) +30 mv c.) +75 mv d.) -35 mv e.) 0 mv part c.) What would be the new resting potential, discounting the effects of non-gated chloride channels (just give an approximate value – no calculation is necessary)? a.) about +20 to +25 mV b.) about -30 to -40 mV c.) about +1 to +5 mV d.) close to ENa+ e.) about -10 to -15 mV
With regard to Na+ and K+ equilibrium potentials and the resting and active membrane potentials, write down (a- D the directions of the forces indicated, acting on the ion in the table below under the respective condition(s). NB the examples given. lon Condition Electrical/Chemical force Direction of force Chemical e.g....inward.. ****** Na ENa+ = + 60 mV Electrical a. Chemical e.g. ...outward.. EK+ =- 90 mV Electrical b. Chemical C. Na" Emp = 0 mV Electrical d. Chemical K+ Emp =-20 mV Electrical
An experimental cell line expresses K+ inward rectifier channels, Na+ leak channels, K+ channels activated by the elevated levels of cytosolic Ca2+, Cl- channels activated by PKC, aquaporins, and α-1 adrenergic receptors (GPCRs that activate Gαq/11 signalling pathway). No voltage-gated channels of any kind are present. The resting membrane potential of these cells is about –50 mV, and they are bathed in the standard extracellular solution. The intracellular concentrations of the relevant ions are as follows: K+ 130 mM, Na+ 15 mM, Cl- 30 mM, Ca2+ 10-4 mM. What will happen to the cell volume if α-1 adrenergic receptor agonist is applied to the bath? Explain your answer.