Properties of triglycerides X, Y, and Z based on fatty acid saturation

Steps:

• Examine diagrams: X has all single bonds in chains (saturated), Y has one double bond (monounsaturated), Z has multiple double bonds (polyunsaturated).
• Identify saturation: X is fully saturated, Y and Z unsaturated.
• Classify by type: All are triglycerides with glycerol and three fatty acids; X and Y have even-numbered chains, Z odd.
• Match to query parts: All have fatty acids; Y and Z unsaturated; X and Y solid at room temp; Z liquid.

Why A is correct:

• Matches definitions: Saturated fats (X) lack double bonds (straight chains pack tightly); unsaturated (Y, Z) have double bonds (kinks prevent packing), per lipid structure rules.

Why the others are wrong:

• B: Incorrectly groups X and Y as unsaturated starters, ignoring X's saturation.
• C: Overincludes Z as saturated and misgroups solids.
• D: Reverses saturation and solid groups, violating chain packing principles.

Final answer: A