B2.1.2hi) To explain the structure of function & synthesis of lipids

Question 1

Functions

Answer 1

Energy store
Respiration substrate
Hormones
Components of cell surface membrane
Protection
Insulation (organs & nerves)

Question 2

Structure

Answer 2

Composed of C,H,O
Long hydrocarbon chain
Fats/oils
Phospholipids
Sterols

Question 3

Triglycerides

Answer 3

C3H8O3
Made of glycerol & fatty acids
Fatty acids a long hydrocarbon chains
Fatty acids can be saturated or unsaturated

Question 4

Saturated fatty acids

Answer 4

Carboxyl group COOH
C-C bonds
High melting point
More energy to be hydrolyzed
Animal fats- solid

Question 5

Unsaturated fatty acids

Answer 5

COOH
C=C bonds
Double bond- causes a kink in chain
Low melting point
Less energy to be hydrolyzed
Plant fats- liquid

Question 6

Phospholipid

Answer 6

Main component of the cell surface membrane
2 fatty acid chains
Glycerol head & phosphate group
Amphipathic- dual nature
Head- polar & hydrophilic
Tail- non polar & hydrophobic
Oil is less dense than water- oil floats
Oil in water- head appears as globules & tails more in away from the water
Phospholipid bilayer- cell surface membrane