Cholesterol is transported in the blood within which structures?

• A. Glucose
• B. Red blood cells
• C. White blood cells
• D. Lipoproteins

Answer: (D)

Cholesterol is hydrophobic and won’t dissolve in blood on its own, so it needs to be packaged into carriers. Lipoproteins are the particles that do this job. They are complexes of lipids surrounded by a surface of phospholipids, cholesterol, and specific proteins called apolipoproteins, with a core that contains cholesterol esters and triglycerides. This structure lets cholesterol travel through the watery blood to tissues and the liver.

That’s why cholesterol is transported in the blood within lipoproteins. Glucose travels dissolved in plasma and moves into cells via glucose transporters, not packaged lipoproteins. Red blood cells and white blood cells aren’t carriers for cholesterol; they have other primary roles—oxygen transport and immune defense, respectively.