Deck 23: Carbohydrates

Question 1

Amylose is a polysaccharide with ________ linkages.

A) a-1,4'-glycosidic
B) a-1,6'-glycosidic
C) b-1,4'-glycosidic
D) b-1,6'-glycosidic

Answer 1

a-1,4'-glycosidic

Question 2

Cellulose is a polysaccharide with ________ linkages.

A) a-1,4'-glycosidic
B) b-1,6'-glycosidic
C) b-1,4'-glycosidic
D) a-1,6'-glycosidic

Answer 2

b-1,4'-glycosidic

Question 3

Which of the following is D-glucose?

A) I
B) II
C) III
D) IV

Answer 3

III

Question 4

Which of the following is D-fructose?

A) I
B) IV
C) II
D) III

Question 5

What are the products of the following reaction?

A) D
B) A
C) C
D) B

Question 6

After a series of Kiliani-Fischer syntheses on D-glyceraldehyde, an unknown sugar was isolated from the reaction mixture. The following experimental data was obtained. What is the structure of this unknown sugar?
Data:
- Molecular formula: C₆H₁₂O₆
- Reacts with phenylhydrazine to give an osazone, mp 178°C.
- Reacts with HNO₃ to give an optically active aldaric acid.
- Wohl degradation followed by HNO₃ oxidation gives an optically inactive aldaric acid.
- Two Wohl degradations followed by HNO₃ oxidation give a meso-tartaric acid.

A) D
B) C
C) A
D) B

Question 7

What type of linkage is present in chitin?

A) beta-1,2'-glycosidic linkage
B) alpha-1,2'-glycosidic linkage
C) alpha-1,4'-glycosidic linkage
D) beta-1,4'-glycosidic linkage

Question 8

What is the composition of sucrose?

A) Repeating unit of glucose units joined in a b-1,4'-glycosidic linkage
B) Two glucose units with a a-1,4'-glycoside bond
C) One galactose and one glucose unit with a b-1,4'-glycoside bond
D) One glucose and one fructose unit with a a-glycosidic bond to the 2' carbon of a fructofuranose ring