LipidsEdexcel A-Level Biology B: Mind map

Exam questions on Lipids

1. A food technologist is comparing two cooking fats. Butter is solid at room temperature and contains mostly saturated fatty acids, whereas olive oil is liquid at room temperature and contains mostly unsaturated fatty acids.
   Explain why olive oil is liquid at room temperature but butter is solid.2 marks
2. A camel stores fat in its hump, which it can use as an energy reserve in the desert. A seal living in cold Arctic water has a thick layer of fat, called blubber, under its skin.
   Explain how the blubber helps the seal to survive in cold water.2 marks
3. A student uses a model kit to build a triglyceride. The model contains one glycerol molecule and three fatty acid molecules. Two of the fatty acids each contain one C=C double bond in the hydrocarbon chain and the third has no C=C double bonds.
   Describe how the glycerol and fatty acids in the model are joined to form a triglyceride.3 marks