Question

The phospholipids of the lipid bilayer align themselves so that the nonpolar, hydrophobic region is located:

A) Externally, facing the extracellular environment

B) Internally, facing the cytoplasmic environment

C) Alternately, facing both extracellular and cytoplasmic environments

D) Randomly, with no specific orientation

Answer 1

The nonpolar, hydrophobic tails of phospholipids in the cell membrane face each other on the inside of the lipid bilayer, away from the watery intracellular and extracellular environments.

Step-by-step explanation:

The phospholipids in the lipid bilayer of cell membranes arrange themselves so their hydrophilic heads face the aqueous environments on both the inside and the outside of the cell, while their hydrophobic tails face each other internally, away from water. This orientation is because the phosphate groups of the phospholipid heads are polar and are therefore attracted to the intracellular and extracellular fluid, which are water-based. Conversely, the lipid tails are nonpolar and hydrophobic and prefer to be shielded from water, thus they are oriented towards the interior, forming the bilayer's nonpolar, hydrophobic region.