Deck 17: Carbohydrates

Question 1

What is the relationship between the following compounds?

A) anomers
B) meso compounds
C) enantiomers
D) identical structures

Answer 1

anomers

Question 2

Assign the stereocenters in D-Galactose according to the S/R-system.

A) 2R, 3R, 4R, 5R
B) 2R, 3R, 4S, 5S
C) 2R, 3S, 4S, 5R
D) 2S, 3S, 4R, 5R

Answer 2

2R, 3S, 4S, 5R

Question 3

Which reagents could be used to convert galactose to galacturonic acid?
I. NaBH₄ / H₂O
II. Tollens' solution (aqueous silver nitrate and ammonia)
III. Benedict's solution (aqueous sodium carbonate, copper(II)sulfate and sodium citrate)
IV. Ni / H₂

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

Answer 3

II, III

Question 4

Which sugars are monosaccharides?
I. mannose
II. maltose
III. ribose
IV. lactose
V. glucose

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

Question 5

Which sugars and classifications are correctly matched?
I. D-Glucose and aldohexose
II. D-Galactose and aldopentose
III. D-Ribose and ketopentose
IV. D-Fructose and ketohexose
V. D-Mannose and ketohexose

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

Question 6

The Fischer projection for L-idose corresponds to which Haworth projection?

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

Question 7

What is the relationship between the following compounds?

A) anomers
B) diastereomers
C) enantiomers
D) identical structures

Question 8

Which reagents could be used to convert galactose to galactitol?
I. NaBH₄ / H₂O
II. Tollens' solution (aqueous silver nitrate and ammonia)
III. Benedict's solution (aqueous sodium carbonate, copper(II)sulfate and sodium citrate)
IV. Ni / H₂

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

Question 9

How many stereoisomers are there in a 2-ketohexose?

A) 2
B) 3
C) 8
D) 16

Question 10

Which sugars and classifications are correctly matched?

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

Question 11

What is the relationship between the following compounds?

A) enantiomers
B) anomers
C) meso compounds
D) diastereomers

Question 12

Which of the labeled atoms is the anomeric carbon?

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

Question 13

Which monosaccharides have the D configuration?

A) I, IV, V
B) II, III, VI
C) IV, V
D) IV, VI

Question 14

Which is the correct structure for $\alpha$ -D-glucopyranose?

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

Question 15

How many pairs of enantiomers are there in an aldohexose?

A) 2
B) 3
C) 4
D) 8

Question 16

How many stereocenters are there in a 2-ketohexose?

A) 2
B) 3
C) 8
D) 16

Question 17

Which of the labeled bonds is a glycosidic bond?

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

Question 18

How many carbon atoms in an aldohexose are NOT stereocenters?

A) 2
B) 3
C) 8
D) 16

Question 19

Which is the correct structure for D-glyceraldehyde?

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

Question 20

Which compounds and functional types are correctly matched?

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

Question 21

Morphine-6-glucuronide (active) and morphine-3-glucuronide (inactive) are both metabolites of morphine found in humans. The accumulation of morphine-glucuronides can lead to kidney failure. The chemical connection between morphine and glucuronide belongs to which classes of compounds? I) glycoside
II) ester
III) ether
IV) acetal

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

Question 22

Complete the following reaction by providing the reagent needed.

Question 23

The $\alpha$ -furanose form of D-Fructose is

Question 24

Sucrose is a disaccharide from sugar cane and sugar beets consisting of the following monosaccharides:

A) D-Glucopyranose and D-Fructofuranose
B) L-Galactopyranose and D-Fructofuranose
C) D-Glucofuranose and D-Fructopyranose
D) L-Glucopyranose and D-Galactopyranose

Question 25

Which will reduction of D-fructose with NaBH₄ yield?

A) a single chiral alditol
B) a pair of enantiomeric alditols
C) a meso compound
D) two diastereomers

Question 26

$\beta$ -D-Glucopyranose ( $\beta$ -D-Glucose) and dissolved oxygen are converted by the enzyme glucose oxidase into D-Gluconic acid, and an inorganic byproduct. This reaction is used to measure the glucose-content in blood. What is the inorganic byproduct?

A) H₂O
B) H₂O₂
C) 2-methylaniline
D) a blue dye

Question 27

Complete the following reaction by providing the products of the reaction.

Question 28

Which are reducing sugars?
I. lactose
II. sucrose
III. glucose
IV. fructose
V. galactose

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

Question 29

Lactose, which makes up between 2 to 8 percent of milk (depending on the species) is a disaccharide, in which D-Galactose and D-Glucose are linked. What type of glycosidic bond can you discern?

A) " $\beta$ -1,4 glycosidic bond"
B) " $\alpha$ -1,4 glycosidic bond"
C) " $\beta$ -1,2 glycosidic bond"
D) " $\alpha$ -1,2 glycosidic bond"

Question 30

Maltose is a disaccharide formed from two units of D-Glucose. The production of maltose from germinating cereal grains (such as barley) is called malting, which is the first step of the brewing process. During germination, the concentration of amylases, which are the enzymes producing maltose from starch, is maximal. Maltose is then consumed by yeast, which produces ethanol and carbon dioxide. What type of glycosidic bond can you discern?

A) " $\beta$ -1,4 glycosidic bond"
B) " $\alpha$ -1,4 glycosidic bond"
C) " $\beta$ -1,2 glycosidic bond"
D) " $\alpha$ -1,2 glycosidic bond"

Question 31

Cellulose, starch, and glycogen are polysaccharides that contain which sugar?

A) sucrose
B) glucose
C) fructose
D) lactose

Question 32

Which sugars are reducing sugars?
I. sucrose
II. maltose
III. lactose
IV. fructose

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

Question 33

Which are disaccharides?
I. sucrose
II. glucose
III. maltose
IV. lactose
V. galactose

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

Question 34

Which statements about the following sugar are true? I) It is a reducing sugar.
II) It will undergo mutarotation.
III) The linkage is 1,1'.
IV) It is composed of two units of D-glucose.

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

Question 35

Which components react to form adenine-deoxyribonucleoside?

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

Question 36

Two sugars produce identical products when treated with NaBH₄. Which of the following are possible structures for the sugars?

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

Question 37

The $\beta$ -pyranose form of D-Galactose is

Question 38

Which of the statements about sucrose is false?

A) The linkage between anomeric carbon atoms is 1,4'.
B) It is the most abundant disaccharide.
C) It cannot reduce Tollens' reagent.
D) It is a disaccharide composed of glucose and fructose.

Question 39

Complete the following reaction by providing the product of the reaction.

Question 40

Complete the following reaction by providing the product of the reaction.

Question 41

The structure of $\beta$ -D-Galacturonic acid is

Question 42

The structure of $\alpha$ -D-Mannose is

Question 43

L-Sorbofuranose reacts with two molecules of acetone. Complete the reaction scheme.

Question 44

2,3,4,6-Di-O-isopropyliden-sorbofuranose undergoes oxidation at a platinum-catalyst and subsequent hydrolysis to 2-Keto-L-gulonic acid. Complete the reaction scheme.

Question 45

D-Glucosamine, D-Mannosamine, and D-Galactosamine are C-2 stereoisomers of each other.

Question 46

Complete the following reaction by providing the reagent needed.

Question 47

Glucose, Galactose, and Fructose are aldohexoses.

Question 48

The structure of cellulose is a(n) _________________ polymer of glucose.

Question 49

Glycogen is a branched component of starch.

Question 50

The structure of D-Gluconic acid is,

Question 51

The structure of D-Mannitol is,

Question 52

Complete the following reaction by providing the product of the reaction.

Question 53

The structure of amylopectin is a(n) __________________ polymer of glucose.

Question 54

Sucrose is an acetal.

Question 55

Draw the structure of D-Sorbitol from the information given.

Question 56

Amylose and amylopectin are unbranched components of starch.

Question 57

$\alpha$ -D-glucopyranose is a hemiacetal.