Lipids

Question 1

What are lipids made of?

Answer 1

Not polymers formed from monomers. Made from a variety of different components but they all contain hydrocarbons. The components theyre made from related the function. Two types to know- triglycerides and phospholipids.

Question 2

Structure of a triglyceride

Answer 2

Contains elements C,H,O
made from glycerol and 3 fatty acids
Joined by 3 ester bonds ( by condensation reaction)
Fatty acid can be saturated or unsaturated

Question 3

functions of triglycerides

Answer 3

Energy source for aerobic respiration
Thermal insulation (polar bears)
Electrical insulation (myelin sheath)
Buoyancy (seals)
Physical protection around organs

Question 4

What is a saturated fatty acid?

Answer 4

Do mot have any double bonds between their carbon atoms
Cause an increase in cholesterol and low density lipoproteins

Question 5

What is an unsaturated fatty acid?

Answer 5

Do have double binds between carbon atoms, which causes the chain to kink
Contains less hydrogen than saturated fatty acids
Kinked at each carbon carbon double bond

Question 6

What is a phospholipid?

Answer 6

a lipid containing a phosphate group in its molecule replacing a fatty acid molecule. The phosphate group is hydrophilic and the fatty acid tails are hydrophobic

Question 7

function of phospholipids

Answer 7

Are the maim molecule in cell membranes
Lipid soluble (non polar) molecules can diffuse through the cell membrane by simple diffusion
Polar or charged molecules cannot diffuse through cell membrane
Phospholipids form a bilayer of cell membranes

Question 8

Cholesterol

Answer 8

Fits within the phospholipid bilayer
Changes the fluidity of the membrane
More cholesterol = less fluid

Question 9

What’s the emulsion test?

Answer 9

For the presence of lipids.
-shake the test substance with ethanol for about a minute then pour the solution into water
Any lipid will show up as a milky emulsion
The more lipid there is the more noticeable the milky colour will be.