Lipids

Question 1

What’s a triglyceride made of

Answer 1

Three fatty acids

One glycerol

Question 2

3ways to classify lipids

Answer 2

Degree of saturation
Source (oil/fat)
Essential or non essential fatty acids

Question 3

Three types of fatty acids

Answer 3

Saturated fatty acids
Mono unsaturated fatty acids
Poly unsaturated fatty acids

Question 4

How does a lipid become saturated

Answer 4

Hydrogen

Question 5

Difference between cis and trans fatty acids

Answer 5

Cis has hydrogen on the same side of the double bonds. Unsaturated fatty acids food

Trans fatty acids have hydrogen on either side of the double bond, developed during processing, bad for yolk

Question 6

What are essential fatty acids

Answer 6

Cannot be made in the body so must be obtained from food

Question 7

Function of EFAs

Answer 7

Cell membranes

Reduce cholesterol

Question 8

Examples of EFAs

Answer 8

Linoleic fish oil

Linolenic corn oil

Question 9

Examples of polyunsaturated fatty acids

Answer 9

Arachidonic acid

Question 10

Sources of omega 3 fatty acid

Answer 10

Oily fish
Fish oil
Nuts seed
Fortified eggs

Question 11

Functions of omega 3 fatty acids

Answer 11

Reduce the risk of CHD, heard attacks and strokes by raising hDL and reducing LDL

Prevent blood clots

Aids foetal brain development and brain functioning

Question 12

Properties of lipids

Answer 12

Solubility
Effect by heat
Plasticity
Rancidity 
Hydrogenation
Emulsions
Stability

Question 13

Melting temp

Answer 13

30-40

Question 14

Boiling point

Answer 14

175-195

Question 15

Smoke point

Answer 15

When lipids are overheated they decompose. It produces a blue haze or smoke and give off an acrid smell

Question 16

Flash point

Answer 16

Extreme overheating causes the vapour to spontaneously ignite

Question 17

How does a fat become more solid

Answer 17

Add hydrogen

More saturated

Question 18

Two types of rancidity

Answer 18

Oxidative (oxygen)

Hydrolytic (enzymes or bacteria break down)

Question 19

Temporary emulsion

Answer 19

Shaking eg vinegariette

Question 20

Permanent emulsion

Answer 20

Using an emulsifier. Eg lecithin in egg for mayonnaise

Question 21

What is a colloidal solution

Answer 21

A solution with suspended microscopic insoluble particles distributed evenly through another substance

Question 22

Biological functions of lipids

Answer 22

Heat and energy
Insulated body (adipose tissue)
Protects important organs
Fat soluble vitamins ADEk
Provide omega 3 fatty acids 
Essential fatty acids

Question 23

Enzyme that breaks down fat

Answer 23

Lipase

Question 24

What does lipase break lipids knot

Answer 24

Fatty acids and glycerol

Question 25

Organs involved in digestion of lipid

Answer 25

Pancreas -pancreatic juice Liver -bile Small intestine -intestinal juice

Question 26

Example of a saturated fatty acid | What’s its plasticity at room temperature

Answer 26

Butyric acid | Solid at room temp

Question 27

Example of a monounsaturated fatty acid | What’s its plasticity at room temperature

Answer 27

Oleic acid in corn | Liquid at room temperature

Question 28

Example of polyunsaturated fatty acid. | What’s its plasticity at room temp

Answer 28

Linoleic acid in nuts and seeds | Soft as room temperature

Question 29

How does oxidative rancidity occur

Answer 29

Oxygen joins with carbon atom in double bond | Releases unpleasant smell

Question 30

How does hydrolytic rancidity occur

Answer 30

Enzymes break fat down into fatty acids and glycerol | Gives unpleasant taste and smell