Which lipid class functions as pigments such as beta-carotene?

• A. Triglycerides
• B. Phospholipids
• C. Steroids
• D. Carotenoids

Answer: (D)

Carotenoids are lipid-soluble pigments. They are isoprenoid lipids that give colors such as orange and yellow to many plants and algae and play a role in light absorption and protection of the photosynthetic apparatus. Beta-carotene is a classic example, serving as a pigment and also as a vitamin A precursor in animals.

Triglycerides store energy, phospholipids form cell membranes, and steroids include hormones and cholesterol-derived molecules, none of which are pigments. That makes carotenoids the lipids that function as pigments like beta-carotene.