Cell membranes are characterized by the presence of
A) triglycerides.
B) phospholipids.
C) unsaturated fats.
D) steroids.
E) saturated fats.

Question

Quizplus · Accepted Answer

Cell membranes consist of a phospholipid bilayer with hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. The hydrophobic tails face inward, while the hydrophilic heads face outward, forming the outer and inner surfaces of the membrane.

Answer: D 
 Some steroids, such as cholesterol, are also present in the cell membrane and help to stabilize the structure of the membrane. However, the main defining characteristic of cell membranes is the presence of phospholipids.

Cell Membranes Are Characterized by the Presence of