Lipids Are Defined by Their Insolubility in Water

Question 1

What are lipids?

Answer 1

nonpolar hydrocarbons; insoluble in water

Question 2

What are the types of lipids and what are their functions?

Answer 2

fats & oils (store energy), phospholipids (structure cell membranes), carotenoids & chlorophylls (capture light energy in plants), steroids & modified fatty acids (hormones & vitamins), animal fat (thermal insulation), lipid coating (electrical insulation), oil & wax (repels water & slows evaporation)

Question 3

What does cis mean?

Answer 3

H atoms on the same side

Question 4

What bonds are cis in unsaturated fats?

Answer 4

double bonds

Question 5

Trans fats

Answer 5

H atoms on opposite sides of the C=C bond

Question 6

Omega-3 fatty acids; purpose

Answer 6

first C=C bond is at position 3 in fatty acid chain; protect against heart disease and stroke

Question 7

phospholipids

Answer 7

fatty acids bound to glycerol; a phosphate group replaces one fatty acid

Question 8

Why is a phospholipid amphipathic?

Answer 8

head/phosphate group is hydrophilic; tails/fatty acid chains are hydrophobic