Can you please explain the answer (it\'s highlighted in red) to this question? 1
ID: 3505770 • Letter: C
Question
Can you please explain the answer (it's highlighted in red) to this question?
16. A neuron has a resting potential of-60 mV. The potassium equilibrium potential is - 90 mV, the sodium equilibrium potential is +60 mV, and the chloride equilibrium potential -65 mV. At the resting potential there are some potassium, sodium, and chloride channels that are open. Which of the following will NOT produce a hyperpolarization from this resting membrane potential? A. Opening more chloride channels B. Opening more potassium channels C. Closing some of the sodium channels D. Opening additional and equal number of both sodium and potassium channels E. Opening additional and equal number of both potassium and chloride channelsExplanation / Answer
Basic concepts required-
Hyperpolarization is when the membrane potential going further negative from resting membrane potential. This can happen by increasing the negative ions in cell or decreasing the positive ions in cell.
Na+ has a greater concentration outside the cell. So, opening of sodium channel will let Na+ ions to go in.
Likewise K+ has greater concentration inside the cell. So, opening of k+ channels will allow it to move outside the cell.
Cl- ions have higher concentration outside the cell. So, opening of chloride channels will let it move inside the cell.
OPTION A. opening of cl- channels will let to chloride entry into the cell i.e negative charge entering the cell. So, the cell become hyperpolarized.
OPTION B. Opening of k+ channels= k+ exit the cell= positive charge goes out= hyperpolarization.
OPTION C. Closing Na+ channel= Na+ enter inside the cell is stopped= reduction in positive charge= hyperpolarization.
OPTION D. Equal number of Na+ and K+ channel open= equal number of Na+ ions get inside cell and K+ ions move out(both are positive ions)= no change in potential.
OPTION E. Equal number of K+ and Cl- channels open= Equal k+ ions move out(positive out) and cl- move in(negative in)= hyperpolarization.