Carbohydrates - disaccharides

Question 1

Reactions of –OH groups in monosaccharides

2 points

Answer 1

1. Intermolecular (occurring between different molecules)

2. Intermolecular condensation - way in which monosaccharides join together to form disaccharides and polysaccharides

Question 2

Two monosaccharide units joined by a

Answer 2

glycosidic bond

Question 3

The glycosidic bond can be

Answer 3

α or β depending on arrangement of –OH on anomeric C

always involve anomeric C of one of the component monnosaccharides

Question 4

Maltose

Answer 4

2 glucose units joined a-(1-4)

Iso-maltose is similar but joined -(1-6)

Formed during the breakdown of starch

Question 5

a-bond vs. b-linkage

2 points

Answer 5

1. Even though some carbohydrates are composed of the same sugars (building blocks) they might differ in linkages
2. they define the final conformation, properties and function of carbohydrates

Question 6

Sucrose

Answer 6

1. 1 fructose (ketohexose) and 1 glucose (aldohexose) joined together
2. a (1-2) if start with glucose. b (2-1) if start with fructose
3. Known as ‘caster sugar’ commercially extracted from sugarcane or beetroot

Question 7

summary

Maltose and isomaltose are disaccharides linked by

Answer 7

a bond

formed during starch breakdown

Question 8

summary

Celllobiose

Answer 8

a disaccharide of Glc joined by b (1-4) linkage

product of cellulose digestion

Question 9

summary

Sucrose

Answer 9

1. a disaccharide from sugarcane or beetroot
2. consisting of Glc and Fru,
3. joined by a(1-2) bond

Question 10

summary

Some carbohydrates are composed of the same building blocks but they differ in

Answer 10

linkages.

Linkages define the final conformation, properties and function of carbohydrates