Lipids

Question 1

What elements do lipids contain?

Answer 1

Carbon, hydrogen and a little bit of oxygen

Question 2

What are lipids made up of?

Answer 2

Glycerol and 3 fatty acids

Question 3

What happens when lipids are put in water?

Answer 3

Nothing they are insoluble

Question 4

They contain a lot of carbon and hydrogen what property does that give them?

Answer 4

Non polar and hydrophobic

Question 5

What happens when you put lipids in alcohol ans other lipids?

Answer 5

They react as they are soluble in other solvents

Question 6

What are the two types of lipids?

Answer 6

Triglycerides and phospholipids

Question 7

How do you know if it is a saturated fatty acid?

Answer 7

Only have single C-C bonds so they form linear hydrocarbon chains

Question 8

What are 4 properties of saturated fatty acids?

Answer 8

Strong attractions between fatty acid chains, high melting points, solid at room temperature and fit closely together in a regular pattern

Question 9

How can you tell if a fatty acid is unsaturated ?

Answer 9

One or more carbon double bonds C=C so the hydrocarbon chain bends due to there being fewer hydrogens they have less energy

Question 10

When a unsaturated fatty acid has one C=C bond what is it called?

Answer 10

Mono unsaturated fatty acid

Question 11

When a unsaturated fatty acid has more than one C=C bond what is it called?

Answer 11

Poly unsaturated fatty acid

Question 12

What are 4 properties of unsaturated fatty acids?

Answer 12

Fewer interactions with fatty acid chains so weaker attractions, low melting points, liquid at room temperature and they push each other apart forming irregular patterns

Question 13

How do you test for lipids?

Answer 13

Emulsion test add ethanol then water.

Question 14

What is the colour change if lipids are present?

Answer 14

Colourless to a milky white emulsion

Question 15

Why do lipids form a milky white emulsion?

Answer 15

Lipids are soluble in ethanol but insoluble in water so ethanol dissolves the lipids s

Question 16

What are triglycerides made up of?

Answer 16

Glycerol head and 3 fatty acid tails

Question 17

What type of molecules are triglycerides?

Answer 17

Non polar hydrophobic moelcules

Question 18

What do the 3 fatty acids determine?

Answer 18

Properties

Question 19

How many hydrocarbons are triglycerides generally made up of?

Answer 19

15-17 carbons

Question 20

What are the glycerol and fatty acids joined together by?

Answer 20

Ester bonds

Question 21

How are triglycerides an important source of water?

Answer 21

High ratio of hydrogen to oxygen atoms so release water when oxidised

Question 22

What do triglycerides hydrophobic properties make them useful for?

Answer 22

Waterproofing agent on feathers leaves and exoskeletons of insects

Question 23

Why are triglycerides an excellent source of energy?

Answer 23

They have a high ratio of energy storing carbon hydrogen bonds to carbon atoms

Question 24

Why are triglycerides a good storage molecule?

Answer 24

Have a low mass to energy ratio so they can store lots of energy in a small amount of space

Question 25

What does their low density mean they are useful for?

Answer 25

Buoyancy, insulation and protection

Question 26

What are phospholipids made up of?

Answer 26

Phosphate polar hydrophilic head and a non polar hydrophobic tail

Question 27

What are phospholipids a component in?

Answer 27

Cell membranes

Question 28

What happens when phospholipids are put in water?

Answer 28

Heads close to water tails in the middle

Question 29

What structure do steroids like cholesterol have?

Answer 29

Four ring structure

Question 30

What are waxes

Answer 30

Similar to fats and oils but are found on leaves and insects