1.1 - Monomers, polymers and carbohydrates

Question 1

What are monomers?

Answer 1

small units from which larger molecules are made

Question 2

What are polymers?

Answer 2

molecules made from a large number of monomers joined together

Question 3

Give three examples of monomers

Answer 3

• monosaccharides
• amino acids
• nucleotides

Question 4

Define condensation reaction

Answer 4

2 molecules join together forming chemical bond, and the elimination of a H2O molecule

Question 5

Define hydrolysis reaction

Answer 5

chemical bond broken between 2 molecules with the use of a H2O molecule

Question 6

What is a monosaccharide?

Answer 6

monomer from which larger carbohydrates are made

Question 7

Give 3 examples of monosaccharides

Answer 7

• glucose
• galactose
• fructose

Question 8

Name the type of bond formed by the condensation of 2 monosaccharides

Answer 8

glycosidic bond

Question 9

How are disaccharides formed?

Answer 9

condensation of 2 monosaccharides

Question 10

Give 3 examples of disaccharides

Answer 10

• maltose
• sucrose
• lactose

Question 11

What is maltose made up of?

Answer 11

2 glucose molecules

Question 12

What is sucrose made up of?

Answer 12

glucose molecule and fructose molecule

Question 13

What is lactose made up of?

Answer 13

glucose molecule and galactose molecule

Question 14

Name the 2 isomers of glucose

Answer 14

• alpha glucose
• beta glucose

Question 15

How are polysaccharides formed?

Answer 15

condensation of many glucose units

Question 16

Which type of glucose are glycogen and starch made up of?

Answer 16

alpha glucose

Question 17

Which type of glucose is cellulose made up of?

Answer 17

beta glucose

Question 18

Give the structure and functions of glycogen

Answer 18

• main energy storage molecule in animals
• 1,4,6 glycosidic bonds
• highly branched: quick release of energy via enzyme action
• large but compact: maximises energy storage
• insoluble: doesn’t affect cell WP + can’t diffuse out of cells

Question 19

Give the structure and functions of starch

Answer 19

• insoluble: doesn’t affect water potential
• branched/helical: makes molecule compact
• polymer of glucose: provides glucose for respiration
• branched: fast breakdown/enzyme action
• large: can’t cross cell membrane/leave cell

Question 20

Name the 2 polysaccharides starch is made up of and describe them

Answer 20

amylose
- unbranched chain
- 1,4 glycosidic bonds
- coiled and compact: stores a lot of energy

amylopectin
- branched chain
- 1,4,6 glycosidic bonds
- side branches: fast enzyme action to release energy

Question 21

Give the structure and function of cellulose

Answer 21

• long, straight chains
• strong microfibrils joined by H bonds: strong cross linkages which provide strength to cell wall
• exerts inward pressure stopping influx of H2O: prevents lysis and maximises SA of plants for photosynthesis

Question 22

Describe the biochemical test for a reducing sugar

Answer 22

• heat with Benedict’s solution
• positive: blue -> brick red

Question 23

Describe the biochemical test for a non-reducing sugar

Answer 23

(after a negative test for reducing sugar)
- heat with acid (HCl) and neutralise with sodium hydrogen carbonate
- heat with Benedict’s solution
- positive: blue -> brick red

Question 24

Describe the biochemical test for starch

Answer 24

• add iodine
• positive: orange/brown -> blue/black

Question 25

What are reducing sugars?

Answer 25

all monosaccharides and some disaccharides e.g maltose, lactose