Lipids

Question 1

What elements to lipids contain?

Answer 1

Hydrogen
Carbon
Oxygen

Question 2

What are the 2 types of lipids?

Answer 2

Triglycerides
Phospholipids

Question 3

What is the function of triglycerides?

Answer 3

Found in foods and used by the body as storage and an energy source

Question 4

What is the function of phospholipids?

Answer 4

Forms a bilayer in the cell membrane

Question 5

What makes up a triglyceride?

Answer 5

1 glycerol
3 fatty acids

Question 6

How are triglycerides joined together?

Answer 6

Ester bonds are formed from a condensation reaction and release 3 water molecules

Question 7

What is the formula for a fatty acid?

Answer 7

RCOOH

Question 8

What is the make up of a fatty acid?

Answer 8

Hydrocarbon chain
Carboxylic acid

Question 9

What is the difference between a saturated fatty acid and an unsaturated fatty acid?

Answer 9

Saturated fatty acids DO NOT contain double bonds between hydrogen atoms
Unsaturated fatty acids HAVE double bonds between hydrogen atoms

Question 10

What is a phospholipid made from?

Answer 10

1 glycerol molecule
1 phosphorus group
2 fatty acids

Question 11

What does hydrophobic mean?

Answer 11

Repels water

Question 12

What does hydrophilic mean?

Answer 12

Attracts water

Question 13

Why are triglycerides insoluble in water?

Answer 13

Fatty acid tails are hydrophobic so they repel water

Question 14

Why do phosphate heads attract water?

Answer 14

They are hydrophillic

Question 15

How do triglycerides arrange themselves?

Answer 15

Hydrophobic fatty acid tails point away from water
Hydrophilic phosphate heads point towards water

Question 16

What is the test for lipids?

Answer 16

Emulsion test

Question 17

How do you test for lipids?

Answer 17

1. Add 2cm3 ethanol to food sample and shake
2. Then add water and shake
3. If lipids are present, a white emulsion will form