Question

4 main types of ions that contribute to the resting potential

A) Na+, K+, Cl-, Ca2+
B) H+, Mg2+, SO4²-, Fe3+
C) C+, O-, N2, He+
D) P+, S-, I-, Rb+

Answer 1

The resting membrane potential, which is essential for neuron function, is mainly established by the distribution of Na+, K+, and Cl- ions across the cell membrane, facilitated by selective permeability and the sodium-potassium pump. The option (A) is correct.

Step-by-step explanation:

The resting membrane potential is crucial for the proper functioning of neurons and is typically measured between -50 mV to -70 mV. The ions primarily responsible for establishing this potential are Na+ (sodium), K+ (potassium), and Cl- (chloride), with the cell membrane in its resting state being more permeable to K+ and Cl-, and less permeable to Na+.

These ions are distributed unevenly due to selective membrane permeability and the action of the sodium-potassium pump, which pushes out three Na+ ions for every two K+ ions it brings into the cell. This activity, although energy-consuming, is essential in maintaining the resting membrane potential. Without voltage-gated ion channels, which are vital for generating an action potential and for returning the neuron to its resting state, it would be impossible to trigger an action potential. Therefore, option (A) is correct.