Properties of Triglycerides as Lipids

Steps:

• Triglycerides are esters formed from glycerol and three fatty acids, making them nonpolar molecules.
• Nonpolar nature causes hydrophobicity, repelling water.
• Alcohol is a nonpolar solvent, allowing triglycerides to dissolve in it.
• Thus, triglycerides are hydrophobic and soluble in alcohol, matching option D.

Why D is correct:

• Triglycerides consist of long hydrocarbon chains, rendering them hydrophobic per the "like dissolves like" principle, and soluble in nonpolar alcohol.

Why the others are wrong:

• A: Triglycerides are hydrophobic, not hydrophilic.
• B: Triglycerides are hydrophobic, not hydrophilic.
• C: Triglycerides dissolve in alcohol, so not insoluble.

Final answer: D