Lipids

Question 1

Lipids

Answer 1

Organic compounds including fats and oils.

Question 2

Triglycerides

Answer 2

Fats and oils are esters called triglycerides. Triglycerides are a type of liquid - consisting of a glycerol molecule bonded to three long chain carboxylic acids called fatty acids. Triglycerides are formed through a condensation reaction and are non-polar.

Question 3

Fatty acids

Answer 3

Can be saturated (no double bonds between carbons) or unsaturated (double bonds)
Oils contain more unsaturated fatty acids than fats (fats are solid at room temp and oils are liquid)

Question 4

Glycerol + Fatty Acid

Answer 4

Triglyceride molecule + H2O
Hydrogen from glycerol and OH from fatty acid form H2O

Question 5

Saponification

Answer 5

A triglyceride is hydrolysed with a strong base to form glycerol and fatty acid salts (reverse of condensation reaction)
The salts dissociate to form carboxylate ions - soap molecules
Carboxylate ions are made up of a long hydrophobic tail (non-polar) and a hydrophilic head (polar)
The tails of the carboxylate ions gather together and the heads face outwards towards the water
Tails attract oil particles, heads interact with water

Question 6

The cleaning action of soap in hard water is impaired because

Answer 6

The hydrophilic ends react with calcium ions to form insoluble salts