Question

Which of the following would be good evidence that the negative resting potential of a cell is due to Cl- diffusing in ? (choose all that are correct)

- Anoxia causes an immediate large change in the membrane potential

- When Cl- channel blockers are applied, the membrane potential goes toward zero

- When Cl- concentrations outside the cell are raised, the membrane potential becomes more positive

-When Cl- concentrations are raised outside the cell, the membrane potential becomes more negative

Answer 1

Which of the following would be good evidence that the negative resting potential of a cell is due to Cl- diffusing in ?

When Cl- channel blockers are applied, the membrane potential goes toward zero

When Cl- concentrations are raised outside the cell, the membrane potential becomes more negative.

Concentration gradient of ions across membrane set up the voltage called membrane potential.Typical membrane potential ranges between –40 mV to –70 mV. Potassium ion is higher in concentration intracellularly whereas sodium and chloride are at high concentrations in the extracellular region. Hyperpolarization is when the cells become more negative. It is often associated with potassium ion efflux, chloride ion influx through chloride channles.When the chloride ions are kept open at the synapses, it causes diffusion of Cl- into cell making inside of the cell more negative which inhibit firing an action potential. Therefore, blocking of the channel raise the potention towards zero.