Shared structural features of triglycerides and phospholipids

Steps:

• Recall triglycerides consist of glycerol esterified to three fatty acids, while phospholipids have glycerol esterified to two fatty acids and a phosphate group.
• Identify common elements: both are lipids with glycerol backbone and fatty acid chains, making them amphipathic or hydrophobic.
• Match to features: feature 1 (glycerol + fatty acids), feature 2 (lipids/ester bonds), and feature 4 (hydrophobic properties) apply to both.
• Eliminate feature 3 (e.g., membrane formation via polar heads), which is specific to phospholipids.

Why A is correct:

• Triglycerides and phospholipids both contain a glycerol molecule esterified to fatty acids, per lipid biochemistry definitions, covering features 1, 2, and 4.

Why the others are wrong:

• B includes feature 3, unique to phospholipids for bilayer formation.
• C omits feature 1, a core structural component of both.
• D ignores features 1 and 4, essential to their classification as glycerolipids.

Final answer: A