Question

the potential difference across the cell membrane is due to the unequal distribution of ______ across the membrane.

○ phospholipids and proteins
○ cations and anions
○ carbohydrate molecules
○ acids and bases
○ water molecules

Explanation:

The potential difference (membrane potential) across the cell membrane is caused by the unequal distribution of charged particles (ions) like cations (e.g., Na⁺, K⁺) and anions (e.g., Cl⁻) across the membrane. Phospholipids and proteins form the membrane structure, carbohydrates are for cell recognition, acids/bases aren't the main cause, and water distribution doesn't create the potential difference. So the correct option is the one with cations and anions.

Answer:

B. cations and anions