Question

question which of the following statements regarding the maintenance of the membrane potential is correct? select all that apply destruction of the lipid bilayer will disrupt the charge gradient. there is an unequal distribution of anion and cations across the membrane. there are more anions in the ecf than in icf. there are more cations in the ecf than in icf.

Explanation:

1. Destruction of the lipid bilayer will disrupt the charge gradient: The lipid bilayer is the structure of the cell membrane. The charge gradient (membrane potential) relies on the selective permeability of the membrane (due to the lipid bilayer and ion channels). If the lipid bilayer is destroyed, the membrane's integrity and selective permeability are lost, so the charge gradient (which depends on ion distribution across the membrane) will be disrupted. This is correct.
2. There is an unequal distribution of anion and cations across the membrane: Membrane potential is maintained by the unequal distribution of ions (both anions and cations) across the cell membrane. For example, there are more $K^+$ inside the cell (ICF) and more $Na^+$, $Cl^-$ outside (ECF) in a resting neuron. So this unequal distribution is key to membrane potential. This is correct.
3. There are more anions in the ECF than in ICF: In reality, there are more anions in the intracellular fluid (ICF) than in the extracellular fluid (ECF). Many organic anions are trapped inside the cell, so this statement is incorrect.
4. There are more cations in the ECF than in ICF: For example, $Na^+$ (a cation) is more concentrated in ECF, and $K^+$ (a cation) is more concentrated in ICF, but overall, the total number of cations in ECF (due to high $Na^+$) is more than in ICF. Also, considering other cations, the ECF has a higher concentration of cations relative to ICF in terms of the ones contributing to membrane potential (like $Na^+$). This is correct.

Answer:

• Destruction of the lipid bilayer will disrupt the charge gradient.
• There is an unequal distribution of anion and cations across the membrane.
• There are more cations in the ECF than in ICF.