1.2 Lipids

Question 1

What is a saturated lipid?

Answer 1

carbon atoms joined by single covalent bonds - no double bonds

Question 2

What is an unsaturated lipid?

Answer 2

carbon atoms joined by 1 or more double bonds

Question 3

How is a triglyceride formed?

Answer 3

glycerol combines with 3 fatty acids and a condensation reaction occurs.
- a bond is formed between
carboxyl group of fatty acid and
hydroxyl group of glycerol
- a molecule of water is removed
from each reaction = 3
molecules of water removed

triglyceride is formed with an ester bond

Question 4

What is the condensation reaction of a triglyceride called and what bond is formed?

Answer 4

esterification
ester bond

Question 5

Why are lipids a good energy store?

Answer 5

lipids, especially triglycerides, store around 3x more energy as carbohydrates (in the same mass)

Question 6

Why are lipids a good insulator?

Answer 6

-a fatty sheath insulates nerves so electrical impulses move faster
-protect against heat loss

Question 7

How do lipids waterproof organisms?

Answer 7

lipids are hydrophobic
oils - waterproofing fur and feathers
waxes - waterproof insects and plants

Question 8

Describe the structure of a phospholipid?

Answer 8

hydrophilic - phosphate + glycerol head
hydrophobic - fatty acid tail