How Would the Permeability of the Phospholipid Bilayer of Plasma

Question

How would the permeability of the phospholipid bilayer of plasma membranes be described?
A) The bilayer is always impermeable to small molecules.
B) The bilayer is always permeable to charged atoms and molecules.
C) The bilayer is differentially permeable.
D) The bilayer is impermeable to all atoms and molecules.

Accepted Answer

The phospholipid bilayer of plasma membranes is differentially permeable, meaning it is selectively permeable to certain molecules while restricting the passage of others. Small and nonpolar molecules such as oxygen and carbon dioxide can diffuse freely through the bilayer, while polar and charged molecules such as ions and glucose require specific transport proteins or channels in order to cross the membrane.