Deck 14: Biomolecules: Carbohydrates

Question 1

Describe the fundamental difference between the following classifications of carbohydrates.

Answer 1

Question 2

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

Answer 2

a ketohexose

Question 3

Instructions: Refer to the equilibrium below to answer the following question(s). Refer to instructions. The correct name for the cyclic structure is____.

A) a-L-ribofuranose
B) b-D-ribofuranose
C) a-L-ribopyranose
D) b-D-ribopyranose

Answer 3

B

Question 4

Draw the structure of the product of the following reaction.

Question 5

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 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. _____ oxidizes to an optically inactive aldaric acid.

Question 7

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 8

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

Question 9

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 10

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 11

Instructions: Refer to the monosaccharides below to answer the following question(s).
Refer to instructions. Provide the complete name for the a-anomer of rhamnose in its pyranose form.

Question 12

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

Question 13

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 a or b anomer?

Question 14

What is the correct structure for a-D-glucopyranose?

A)
B)
C)
D)

Question 15

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

Question 16

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

Question 17

Convert the following Fisher projections into tetrahedral representations.

Question 18

Instructions: Refer to the monosaccharides below to answer the following question(s).
Refer to instructions. Draw both chair conformations of the a-anomer of rhamnose in its pyranose form. Circle the more stable conformation.

Question 19

Instructions: Label each pair of stereoisomers as:

Question 20

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 21

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 22

Instructions: Consider the reaction below to answer the following question(s). Refer to instructions. Compound Z is:

A) the D-anomer.
B) the a-anomer.
C) the b-anomer.
D) the L-anomer.

Question 23

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

Question 24

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 25

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

Question 26

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

Question 27

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 28

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 29

The monosaccharide shown below is

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

Question 30

Refer to the carbohydrate below to answer the following questions.

Question 31

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

Question 32

Draw the Fisher projection of L-mannose.

Question 33

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

Question 34

Use the information below to answer the following questions.

Question 35

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

Question 36

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

Question 37

How many D-ketotetroses could exist?

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

Question 38

Complete the equation for the following reaction.

Question 39

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 40

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

Question 41

Which of the following is a disaccharide?

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