Triglycerides

Question 1

Define lipids

Answer 1

A group of substances that are soluble in alcohol rather than in water

Question 2

Define macromolecule

Answer 2

A large biological molecule

Question 3

Define phospholipid

Answer 3

A molecule consisting of glycerol, two fatty acids and a phosphate group

Question 4

What are the characteristics of a lipid?

Answer 4

Contain a large amount of carbon and hydrogen atoms and a small amount of oxygen atoms
Insoluble in water
Soluble in alcohol

Question 5

What is an essential fatty acid?

Answer 5

A fatty acid that must be ingested completely and not broken down

Question 6

Describe glycerol

Answer 6

H H H
H-C-C-C-H
OH OH OH

Question 7

What do fatty acids contain?

Answer 7

A carboxyl group at one end

A hydrocarbon tail

Question 8

How many carbons are in the hydrocarbon tail of a fatty acids?

Answer 8

2-20

Question 9

Why are fatty acids, acids?

Answer 9

The carboxyl group can ionise hydrogen therefore it is an acid as it can produce free H+ ions

Question 10

What does a saturated fatty acid not contain?

Answer 10

Double carbon bond

Question 11

What do unsaturated fatty acids have?

Answer 11

Double carbon bonds

Question 12

What does the double carbon bond in a unsaturated fatty acid inhibit?

Answer 12

Hydrogen atoms can binding to the molecule

Question 13

What does polyunsaturated and monounsaturated mean?

Answer 13

Poly = more than one double carbon bond
Mono = one double carbon bond

Question 14

What do double carbon bonds do?

Answer 14

Provide a kink making the molecule more fluid

Question 15

When does an ester bond appear?

Answer 15

During the condensation reaction the water is given off creating a covalent bond between the glycerol and fatty acids. This is an ester bond

Question 16

What are the five functions of lipids?

Answer 16

Energy source
Energy store
Insulation
Buoyancy
Protection