Duration: 1 hour 15 minutes.
ANSWER ALL QUESTIONS
Question One
Lipids are molecules that contain hydrocarbons and make up the building blocks of the structure
and function of living cells. Examples of lipids include fats, oils, waxes, certain vitamins (such
as A, D, E and K), hormones and most of the cell membrane that is not made up of protein.
Lipids are not soluble in water as they are non-polar, but are thus soluble in non-polar solvents
such as chloroform.
a. List the classes of Lipids. (4 marks)
b. Draw the structure of an omega-6 fatty acid 16:1 and Palmitoleic acid (2 marks)
c. Illustrate the formation of a triglyceride (4 marks)
Question Two
A student at university of Lusaka ingested large amounts of sucrose. His body responded by
transforming the glucose and fructose that exceeded his caloric requirements to fatty acids for
triacylglycerol synthesis. This process consumes acetyl-CoA, ATP, and NADPH.
a. Explain how cells produce acetyl-CoA, ATP, and NADPH from glucose. (6 marks)
b. Describe the regulation of fatty acid synthesis. (4 marks)
c. Explain how acetyl-CoA is transported from the mitochondria to the cytosol for fatty
acid biosynthesis. (5 marks)
