Lipids

Question 1

What are the components of lipids (triglycerides and phospholipids)

Answer 1

Triglycerides: 1x Glycerol, 3x fatty acids
Phospholipid: Glycerol, 2x fatty acid, 1x phosphorus

Question 2

What bonds are formed when monomers of lipids condense together?
What is the structure of this?

Answer 2

Ester bonds are formed.
C-O-C=O

Question 3

Explain the difference between unsaturated and saturated fatty acids and what does this mean their properties in room temperature are?

Answer 3

Unsaturated fatty acids have a double carbon to carbon bond C=C and are liquid at room temp as they have weaker intermolecular forces. Saturated fatty acids have a single carbon to carbon bond, C-C, and are solids at room temperature as they have stronger intermolecular forces between chains.

Question 4

What are the properties of triglycerides?

Answer 4

They are non-polar molecules so they do not interact with water or dissolve in solvents as they have slight charges.
Used as an energy storage molecule.
Insulation under skin surface in adipose.
Protects organs with surrounding adipose tissue.
Water proofing in plants, waxy cuticle prevents water loss.

Question 5

Properties of phospholipids?

Answer 5

The head is a polar molecule so does interact and dissolve in water (hydrophilic).
Tails are non-polar molecules so do not interact with water (hydrophobic).

Question 6

Uses for phospholipids?

Answer 6

Used for plasma membranes, cell and organelle membranes.
Arrange themselves into a phospholipid bilayer.

Question 7

What is the food test for lipids and how is it carried out?

Answer 7

Emulsion test.
Add ethanol and water to the food sample and shake. A white emulsion should form when lipids are present.