Deck 14: Biomolecules: Carbohydrates

Question 1

Instructions: Refer to the monosaccharides below to answer the following question(s).

-Refer to instructions. Draw both chair conformations of the $\alpha$ -anomer of rhamnose in its pyranose form. Circle the more stable conformation.

Answer 1

Question 2

Instructions: Refer to the monosaccharides below to answer the following question(s).
Convert the following Fisher projections into tetrahedral representations.

Answer 2

All have the same tetrahedral representation.

Question 3

Instructions: Convert the Fischer projections into tetrahedral representations, and assign R or S stereochemistry to each.
Convert and assign:

Answer 3

Question 4

Instructions: From the sugars below, choose the one that best fits each of the following description(s). There is only one correct answer for each question.
a D-sugar.

Question 5

Instructions: Refer to the monosaccharides below to answer the following question(s).

-Refer to instructions. Provide the complete name for the $\alpha$ -anomer of rhamnose in its pyranose form.

Question 6

Instructions: Refer to the sugars below to answer the following question(s). Choose the sugar that best fits each description. There is only one correct answer for each question, but sugars may be used more than once. Indicate each answer by the corresponding letter.
Refer to instructions. _____ a ketose and _____ an aldose with two chirality centers

Question 7

Instructions: From the sugars below, choose the one that best fits each of the following description(s). There is only one correct answer for each question.
a sugar with three chirality centers.

Question 8

Instructions: Refer to the sugars below to answer the following question(s). Choose the sugar that best fits each description. There is only one correct answer for each question, but sugars may be used more than once. Indicate each answer by the corresponding letter.
Refer to instructions. _____ oxidizes to an optically inactive aldaric acid.

Question 9

Instructions: Refer to the monosaccharides below to answer the following question(s). Classify each sugar by type; for example, glucose is an aldohexose. a. Sorbose
b. Rhamnose
c. Erythrulose
d. Xylulose
Refer to instructions. Erythrulose is ____________________.

Question 10

Instructions: From the sugars below, choose the one that best fits each of the following description(s). There is only one correct answer for each question.
a sugar which yields a single alditol upon reduction.

Question 11

Instructions: Refer to the monosaccharides below to answer the following question(s).
Refer to instructions. Assign R or S configuration to each chirality center in sorbose.

Question 12

Instructions: Refer to the equilibrium below to answer the following question(s).
Refer to instructions. Classify ribose by carbonyl type and number of carbons.

Question 13

Instructions: Convert the Fischer projections into tetrahedral representations, and assign R or S stereochemistry to each.
Convert and assign:

Question 14

Instructions: Refer to the equilibrium below to answer the following question(s).

-Refer to instructions. The correct name for the cyclic structure is____.

A)( $\alpha$ -L-ribofuranose)
B)( $\beta$ -D-ribofuranose)
C)( $\alpha$ -L-ribopyranose)
D)( $\beta$ -D-ribopyranose)

Question 15

Describe the fundamental difference between the following classifications of carbohydrates.

A)monosaccharide, disaccharide, polysaccharide
B)simple sugar, complex sugar
C)ketose, aldose
D)furanose, pyranose

Question 16

Instructions: Refer to D-idose below to answer the following question(s).
Refer to instructions. The Fischer projection for D-idose (above) corresponds to which pyranose below?

A)
B)
C)
D)

Question 17

Instructions: Refer to the sugars below to answer the following question(s). Choose the sugar that best fits each description. There is only one correct answer for each question, but sugars may be used more than once. Indicate each answer by the corresponding letter.
Refer to instructions. _____ a dextrorotary hexose and ______ a levorototary tetrose.

Question 18

Instructions: Refer to the equilibrium below to answer the following question(s).

-Refer to instructions. Which enantiomer of ribose is drawn, D or L, and is it the $\alpha$ or $\beta$ anomer?

Question 19

Instructions: Refer to the monosaccharides below to answer the following question(s). Classify each sugar by type; for example, glucose is an aldohexose. a. Sorbose
b. Rhamnose
c. Erythrulose
d. Xylulose
Refer to instructions. Sorbose is ____________________.

Question 20

Instructions: From the sugars below, choose the one that best fits each of the following description(s). There is only one correct answer for each question.
a deoxy sugar.

Question 21

If the following compound undergoes oxidation in the presence of the appropriate enzyme, draw the structure of the likely product.

Question 22

Instructions: Consider the reaction below to answer the following question(s).
Refer to instructions. Q and Z are cyclic examples of:

A) acetals
B) hemiacetals
C) alditols
D) hemialditols

Question 23

Instructions: Draw structures for the products you would expect to obtain from reaction of $\beta$ -D-galactopyranose with the listed reagents. Be sure to include all relevant stereochemistry. $\beta$ -D-galactopyranose

-Draw:
NaBH₄ in H₂O

Question 24

Instructions: Choose a structure from the list provided below that best fits the description given. There is only one correct answer for each question.

A non-reducing disaccharide

A)
B)
C)
D)
E)
F)

Question 25

Complete the equation for the following reaction.

Question 26

Draw the structure of the product of the following reaction.

Question 27

The monosaccharide shown below is

A) an aldohexose
B) an aldopentose
C) an aldotetrose
D) a ketohexose
E) a ketopentose

Question 28

Draw the Fisher projection of L-mannose.

Question 29

Using the following structure of D-talose as a guide, draw the structure for $\alpha$ -D-talopyranose. Label each ring substituent as axial or equatorial.

Question 30

Instructions: Draw structures for the products you would expect to obtain from reaction of $\beta$ -D-galactopyranose with the listed reagents. Be sure to include all relevant stereochemistry. $\beta$ -D-galactopyranose

-Draw:
CH₃I, Ag₂O

Question 31

Instructions: Draw structures for the products you would expect to obtain from reaction of $\beta$ -D-galactopyranose with the listed reagents. Be sure to include all relevant stereochemistry. $\beta$ -D-galactopyranose

-Draw:
Br₂, H₂O

Question 32

Instructions: Choose a structure from the list provided below that best fits the description given. There is only one correct answer for each question.


-A 1,4' $\beta$ -glycoside

A)
B)
C)
D)
E)
F)

Question 33

Instructions: Consider the reaction below to answer the following question(s).
Refer to instructions. Place a triangle around the anomeric carbon in compound Q.

Question 34

Instructions: Draw structures for the products you would expect to obtain from reaction of $\beta$ -D-galactopyranose with the listed reagents. Be sure to include all relevant stereochemistry. $\beta$ -D-galactopyranose

-Draw:
(CH₃CO)O₂, pryridine

Question 35

Instructions: Choose a structure from the list provided below that best fits the description given. There is only one correct answer for each question.

amylopectin

A)
B)
C)
D)
E)
F)

Question 36

Instructions: Consider the reaction below to answer the following question(s).
Refer to instructions. Which anomer is the LEAST stable?
Q or Z

Question 37

Instructions: Choose a structure from the list provided below that best fits the description given. There is only one correct answer for each question.

A reducing monosaccharide

A)
B)
C)
D)
E)
F)

Question 38

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

A)
B)
C)
D)

Question 39

Instructions: Choose a structure from the list provided below that best fits the description given. There is only one correct answer for each question.

cellulose

A)
B)
C)
D)
E)
F)

Question 40

Instructions: Consider the reaction below to answer the following question(s).

-Refer to instructions. Compound Z is:

A) the D-anomer.
B) the $\alpha$ -anomer.
C) the $\beta$ -anomer.
D) the L-anomer.

Question 41

What is the relationship between D-erythrose and D-threose?

A) they are constitutional isomers
B) they are enantiomers
C) they are diastereomers
D) they are tautomers

Question 42

Which of the following is a disaccharide?

A) glucose
B) fructose
C) sucrose
D) N-acetylgalactosamine
E) both c and d

Question 43

Which of the following could not form a pyranose?

A) D-threose
B) D-ribose
C) D-lyxose
D) D-glucose
E) D-galactose

Question 44

Refer to the carbohydrate below to answer the following questions. a)Which carbon in the carbohydrate is the anomeric carbon?
b)Does this represent an $\alpha$ or $\beta$ -anomoer?

Question 45

Draw an aldopentose with S,S,R stereochemistries at its carbons 2 through 4.

Question 46

How many D-ketotetroses could exist?

A) none
B) one
C) two
D) four
E) eight

Question 47

Which of the following has a D-configuration?

A) only 1 and 2
B) only 1 and 3
C) only 2 and 3
D) only 1, 2 and 3

Question 48

Which reagent would be best suited for the transformation shown?

A) alkaline Cu²⁺ in H₂O
B) Ag⁺ in H₂O/NH₃
C) H₂, with Ni catalyst
D) NaNO₃ at 0 $\degree$ C
E) NaBH₄ in H₂O