Triglycerides

Question 1

What is the structure of triglycerides?

Answer 1

• Non-polar macromolecules
• Formed by 1 glycerol and 3 fatty acid molecules
• Glycerol is always the same, fatty acids vary
• Fatty acids = carboxyl group (COOH) + hydrocarbon tail

Question 2

What bonds are formed between the glycerol and each fatty acid?

Answer 2

Ester bond

Question 3

Why are triglycerides not polymers?

Answer 3

Because they don’t have a series of repeating units

Question 4

What are the 2 types of fatty acids?

Answer 4

Saturated and unsaturated

Question 5

What is a saturated fatty acid?

Answer 5

Where all the carbon bonds are single

Question 6

What is an unsaturated fatty acid?

Answer 6

Where at least one carbon bond is a double

Question 7

What are the structural differences between a saturated and unsaturated fatty acid?

Answer 7

Saturated: can be compacted and act as a protection layer
Unsaturated: Less compact and less dense but are easier to transport

Question 8

Explain the functions of triglycerides.

Answer 8

Energy source: can be broken down in respiration to release ATP, glycerol and fatty acid can be broken down into CO2 + H2O
Energy store: insoluble in water so can be stored without affecting water potential of cell
Insulation: adipose tissue is a store for lipids in whales, which acts as a heat insulator. Lipid in nerve cells acts as an electrical insulator
Buoyancy: fat is less dense than water so is used by aquatic animals to help them stay afloat
Protection: humans have fat around delicate organs (e.g kidneys) to act as a shock insulator.