Biological Molecules (lipids)

Question 1

lipids:

Answer 1

• contain carbon, hydrogen and oxygen
• non-polar
• dissolve in organic solvents

Question 2

structure of triglycerides:

Answer 2

• one glycerol molecule and three fatty acids
• condensation
• ester bond

Question 3

roles of triglycerides:

Answer 3

• energy reserves
• thermal insulation
• protection of delicate internal organs
• metabolic water production when oxidised

Question 4

structure of phospholipids:

Answer 4

• polar (hydrophilic) head: glycerol and phosphate group
• non-polar (hydrophobic) tails of two fatty acids

Question 5

roles of phospholipids:

Answer 5

• biological (cell) membranes
• electrical insulation (myelin sheath of neuron axon)

Question 6

waxes:

Answer 6

• melt above 45 degrees
• waterproofing in terrestrial organisms