Consider the following diagram of a membrane. Which of the following might be the portion of the membrane represented by the letter A?
A)choline
B)tristearin
C)oleic acid
D)glycerol

Question

Consider the following diagram of a membrane.  Which of the following might be the portion of the membrane represented by the letter A?
A)choline 
B)tristearin 
C)oleic acid 
D)glycerol

Quizplus · Accepted Answer

Choline is a component of phosphatidylcholine, which is a major component of cell membranes. The portion labeled A in the diagram appears to be a polar head, which is consistent with the structure of choline in phosphatidylcholine. Tristearin is a triglyceride and is typically found in adipose tissue, not in cell membranes. Oleic acid is a fatty acid that can be a component of cell membranes, but it would not be found in the polar head region. Glycerol is a component of phospholipids, but it is not the polar head region depicted in the diagram.

Consider the Following Diagram of a Membrane