Lipids

Question 1

What bond forms in the condensation reaction between a fatty acid and a glycerol molecule in lipids?

Answer 1

Ester bond.

Question 2

What is the difference between saturated and unsaturated fats?

Answer 2

Saturated fats: no double bonds, solid fats

Unsaturated fats: double bonds, liquids (kinks in chain)

Question 3

What is the name given to molecules made of a glycerol and three fatty acid chains?

Answer 3

Triglyceride

Question 4

What is a phospholipid?

Answer 4

Made up of a glycerol molecule, a phosphate group and two fatty acid chains.
Makes up cell membrane (phospholipid bilayer)
Hydrophilic head and hydrophobic tail

Question 5

Describe a test for lipids

Answer 5

Emulsion test:

• dissolve sample by shaking with ethanol
• pour solution into water in a test tube
• white emulsion should form

Question 6

List functions of lipids

Answer 6

• Insoluble (more fatty acid chains=more insoluble)
• Insulation- eg myelin sheath
• Cell membrane