Lipids

Question 1

What happens when triglycerides are formed by condensation reactions

Answer 1

Fatty acid joins to glycerol molecule and ester bond is formed and molecule of whatever is released
Process happens twice more to form a triglyceride

Question 2

What is the difference between saturated and unsaturated fatty acids

Answer 2

Saturated don’t have any double bonds between carbons so saturated with hydrogen

Unsaturated fatty acids have at least one double bond between carbonS which causes chain to kink

Question 3

What are phospholipids explain the structure

Answer 3

Found in cell membranes
Phosphate group bonded to glycerol and two fatty acids
Phosphate group is hydrophilic and tails are hydrophobic

Question 4

Why are triglycerides good for energy storage?

Answer 4

Hydrocarbon tails contain a lot of energy so lots released when broken down
Insoluble so don’t effect water potential

Question 5

Why are phospholipids good suited to the cell membrane

Answer 5

Heads hydrophilic and tails hydrophobic so they form bilayer
Centre of bilayer is hydrophobic so water double substances can’t easily pass through it

Question 6

What is the test for lipids

Answer 6

Emulsion test
Shake substance with ethanol
Then pour into water
Lipid will show as milky emulsion

Question 7

Explain the structure of triglycerides

Answer 7

Glycerol bonded to 3 fatty acid hydrocarbon tails

Tails hydrophobic so insoluble in water