A Graded Hyperpolarization of a Membrane Can Be Induced By

Question

A graded hyperpolarization of a membrane can be induced by
A) increasing its membrane's permeability to Na⁺.
B) decreasing its membrane's permeability to H⁺.
C) decreasing its membrane's permeability to Cl⁻.
D) increasing its membrane's permeability to Ca⁺⁺.
E) increasing its membrane's permeability to K⁺.

Accepted Answer

Hyperpolarization refers to an increase in the membrane potential that makes the membrane potential more negative than its resting potential. This can be achieved by increasing the membrane's permeability to K⁺ ions, allowing more K⁺ ions to flow out of the cell, leading to an increase in the negative charge on the inside of the membrane. None of the other options would lead to hyperpolarization. Increasing membrane permeability to Na⁺, Ca⁺⁺, or H⁺ would lead to depolarization, and decreasing membrane permeability to Cl⁻ would have no effect on the membrane potential.