Carbohydrates and Organic Compounds: Questions and Naming Rules

Classification and bonding of carbohydrates

1.Draw the mirror image of the following molecule. Is the original molecule an enantiomer of its mirror image? Briefly explain. 

3. Which of the following carbohydrates is an example of a monosaccharide? 

A) Amylose

B) Sucrose

C) Maltose

D) Fructose

E) Lactose

4. Which of the following carbohydrates is an example of a disaccharide?

A) Amylose

B) Fructose

C) Mannose

D) Glucose

E) Lactose

5. Amylopectin and Glycogen are categorized as branched polysaccharides. Which of the following contributes to their difference in branching? 

A) Amylopectin branches every 10-15 glucose units at the a-1,4 position, while glycogen branches every 25 glucose units at the b-1,6 position

B) Amylopectin branches every 10-15 glucose units at the b-1,4 position, while glycogen branches every 25 glucose units at the a-1,6 position

C) Amylopectin branches every 25 glucose units at the b-1,4 position, while glycogen branches every 10-15 glucose units at the b-1,6 position

D) Amylopectin branches every 25 glucose units at the a-1,6 position, while glycogen branches every 10-15 glucose units at the a-1,6 position

E) All of the above are true

6. Which of the following is a common glycosidic bond among amylose, amylopectin, and glycogen?

A) They all contain a b-1,4-glycosidic bond

B) They all contain a a-1,4-glycosidic bond

C) They all contain a a-1,6-glycosidic bond

D) They all contain a b-1,6-glycosidic bond

E) They have nothing in common

7. Why is Sucrose a non-reducing sugar while lactose and maltose are? 

A) The anomeric carbon of glucose is free in sucrose. This allows the ring to open exposing the aldehyde functional group to Benedict’s reagent, while the anomeric carbon of fructose is used to form the glycosidic bond.

B) The anomeric carbons of the monomers that make up lactose and maltose participate in the formation of the glycosidic bond. Thus, neither sugars can open its ring to form the aldehyde functional group.

C) The anomeric carbons of the monomers that make up sucrose both participate in the formation of the glycosidic bond. Thus, neither sugars can open its ring to form the aldehyde or ketone functional group.

D) The benedict’s reagent only tests positive for monosaccharides and not disaccharides

E) None of the above

8. Which of the following carbohydrates is an example of a polysaccharide?

A) Maltose

B) Sucrose

C) Glucose

D) Fructose

E) Cellulose

9. Which of the following best describes the type of glycosidic bond seen below (see where the arrow is pointing):

A) b-1,4-glycosidic bond C) a,b-1,4-glycosidic bond

B) a-1,4-glycosidic bond D) g,g-1,4-glycosidic bond

E) All of the above

10. Which of the following best describes the glycosidic bond of cellulose?

A) b-1,4-glycosidic bond

B) a-1,4-glycosidic bond

C) a-1,6-glycosidic bond

D) b-1,6-glycosidic bond

11. Use the fisher projection to identify if the carbohydrate shown below is the “D” or “L” isomer: (4 points)

a________ b________ c_________ d________

12. Convert the following Fischer Projections into Haworth Structures for the following carbohydrates. DRAW ONLY THE BETA form of each structure 

13. Use the fisher projection to classify the following carbohydrates (i.e. aldoheptose,ketoheptose, etc):

a________ b________ c _________ d________

14. Name the following organic compounds using IUPAC rules of naming: 

15. Draw the skeletal structure for the following organic compounds: 

a. 4-bromo-3-ethylhexanoic acid

b. 4-chloro-2-pentenoic acid

c. ethyl propanoate

d. 5,5-dimethyl-2-hexanamine

e. N-methyl-2-pentanamine

f. 2-chloro-2-methylbutanamide

g. N-ethyl-2-ethylbutanamide

h. N,N-dimethyl-2-iodoethanamide