Lipids

Question 1

Sources of Omega-3 fatty acids

Answer 1

Oily fish
Nuts
Seeds

Question 2

Functions of Omega-3 fatty acids

Answer 2

Reduce risk of CHD.
Aid foetal development during pregnancy.
Improve memory and cognitive functioning.

Question 3

Emulsifiers

Answer 3

Molecules that have a hydrophilic head and a hydrophobic tail.
When an emulsifier is added to a mixture of 2 immiscible liquids…
Hydrophilic head attaches to water.
Hydrophobic tail attaches to oil.
Prevents liquids from separating, creates permanent emulsion.
Eg. Lecithin

Question 4

Oxidative rancidity

Answer 4

Occurs when oxygen in air combines with carbons in double bond of an unsaturated fatty acid.

Question 5

Hydrolytic rancidity

Answer 5

Occurs when enzymes/bacteria break down lipids into glycerol and fatty acids.

Question 6

Plasticity

Answer 6

How soft and malleable a fat is at a given temperature.
Eg. Butter is solid at room temp.

Question 7

Functions of lipids

Answer 7

Supply body with heat and energy.
Supply body with fat-soluble vitamins A, D, E and K - necessary for overall health.