3.5 Lipids

Question 1

What is a triglyceride?

Answer 1

A lipid which is made up of a glycerol molecule and three fatty acids
Properties : compact and insoluble
Roles : Energy storage and insulation

Question 2

What is a phospholipid?

Answer 2

A lipid with a hydrophilic head and hydrophobic tail

Roles: membrane structure

Question 3

What is cholesterol?

Answer 3

A lipid that is…
Properties : small, both hydrophilic and hydrophilic
Role: membrane stability and steroid hormones

Question 4

How are triglycerides synthesised?

Answer 4

Each fatty acid undergoes a condensation. Reaction with one of the OH (alcohol) groups in glycerol.
A hydrolysis reaction breaks down the triglyceride into the original glycerol and fatty acid

Question 5

What is a saturated compound?

Answer 5

A compound with no double bonds

Question 6

What is an unsaturated compound?

Answer 6

A compound with one or more double bonds

Question 7

What test is carried out to identify lipids?

Answer 7

Emulsion test

Question 8

How is the emulsion test carried out?

Answer 8

1. Mix sample with ethanol
2. Mix with water and shake
3. The formation of a white emulsion in too if the solution indicates the presence of a lipid