1.5: Lipids

Question 1

Triglycerides

Answer 1

One molecule of glycerol and 3 fatty acids attached to it

Question 2

Fatty acids made of

Answer 2

hydrocarbons

Question 3

Fatty acids have ‘tails’ which are

Answer 3

hydrophobic

Question 4

Hydrophobic

Answer 4

repel water molecules

water hating

Question 5

Lipids are … in water

Answer 5

insoluble

Question 6

Fatty acids basic structure

Answer 6

1 carbon atom
double bond to oxygen atom
single bond to OH ion
single bond to ‘R’ group

Question 7

R group is

Answer 7

variable group

Question 8

How is fatty acids linked to glycerol

Answer 8

carbon atom on fatty acid

Question 9

Triglycerides formed

Answer 9

condensation reaction

occurs 3 times between each fatty acids w/ the glycerol

Question 10

Bond in triglyceride formation

Answer 10

ester bond

Question 11

Two types of fatty acids

Answer 11

saturated and unsaturated

Question 12

Difference between saturated and unsaturated fatty acods

Answer 12

in the hydrocarbon tails (r groups)

Question 13

Saturated fatty acids

Answer 13

Contain no double bonds between C atoms

‘saturated’ with hydrogen

Question 14

Unsaturated fatty acids

Answer 14

Contain at least one carbon-carbon double bond

cause the chain to kink

Question 15

Lipids found in cell membrane

Answer 15

phospholipids

Question 16

Structure of a phospholipid

Answer 16

Glycerol
phosphate group
2 fatty acids

Question 17

Hydrophilic

Answer 17

Attract water molecules

water loving

Question 18

Whats hydrophilic/phobic in a phospholipid

Answer 18

phosphate group = Hydrophilic

fatty acid tails = Hydrophobic

Question 19

Triglyceride function

Answer 19

Energy storage molecules

Question 20

Where is lots of chemical energy stored

Answer 20

hydrocarbon tails of fatty acids

Question 21

Triglycerides in cells

Answer 21

Clump together as INSOLUBLE DROPLETS

Question 22

Phospholipids make up

Answer 22

bilayer in cell membrane

Question 23

Why is it a bilayer not one layer

Answer 23

hydrophilic heads facing out on either side = double layer

Question 24

Cell membrane acts as a barrier to

why

Answer 24

water-soluble substances

as centre of bilayer is hydrophobic tails

Question 25

Test for lipids

Answer 25

Emulsion test

Question 26

Steps in the Emulsion test

Answer 26

shake the test substance with ethanol so it dissolves
add solution to distilled water
presence of lipid = milky emulsion layer