1) Coconut oil consists almost entirely of fats and oils. The typical fatty acid composition of coconut oil is shown in the following table.

a. State why coconut oil is resistant to oxidative rancidity.
Coconut oil reacts in the body to produce fatty acids.

b. Name the other product of this reaction.

Coconut oil can be metabolised by the body to produce caprylic acid.

c. Write the molecular formula of the molecule found in coconut oil that can be metabolised to produce three caprylic acid molecules.

Solution

Coconut oil contains vitamin E, and negligible quantities of other vitamins and minerals. The structure of vitamin E is given below.

d. Explain why vitamin E is soluble in coconut oil.

Solution

2) Inside the shell of an egg is egg white that encircles egg yolk. The nutrition information for egg yolk and egg white is given in the table below.

a. A linkage has been circled with a dashed line in the lactose molecule shown above.
i. Name the circled linkage.

b.

i. Explain what the GI of a food indicates.

ii. State why the breakdown of lactose, as shown above, contributes to the GI of lactose.

Solution

c. Proline is found both in cow’s milk and in the enzyme lactase. Proline is not an essential amino acid. The structure of proline is shown in the data book.

i. State why proline is not an essential amino acid.

ii.Draw the structure of proline as it would be in an acidic solution.

Solution

Proline is found in proteins throughout the human body.

iii. Identify two types of enzyme-catalysed chemical reactions involving proline in the human body.

iv. Explain why proline has two optical isomers.

v. Only one of proline’s optical isomers is found in lactase. Explain why lactase must contain the correct optical isomer of proline to function as an enzyme in the digestion of cow’s milk.

Solution