Paper 2 · November 2023 · Biological Molecules
Fats and oils are both triglycerides. They differ in that
Aa fat is liquid at room temperature while an oil is solid at the same temperature
Ba fat contains glycerol while an oil is built from fatty acid molecules alone
Ca fat is made only by animals while an oil is made only by bacteria and fungi
Da fat is solid at room temperature while an oil is liquid at the same temperature
Explanation
The difference comes from the fatty acid tails. A fat has mostly saturated tails, which are straight and pack closely, so it stays solid. An oil has unsaturated tails with double bonds that kink the chain, so the molecules cannot pack as tightly and it is liquid at the same temperature.
Derived from ZIMSEC Biology Paper 2, Nov 2023, Q1