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9: Carbohydrates

Carbohydrate structure, glycosidic bonds, biological roles.

LibreTexts reference: Carbohydrates

Determining D and L Configurations from Fischer Projections

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D-tagatose⟶L-tagatose

. . CH2OH
. ==O 
H . . . . OH
. . . .
H . . . . OH
. . . .
H . . . . OH
. . . .
. . CH2OH

Above is a Fischer projection of the monosaccharide D-tagatose. Which one of the following Fischer projections is of the monosaccharide L-tagatose?

 

Determining D and L Configurations from Haworth Projections

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α-D-lyxose

CH2OH . . .  O  . . . H
. . ⟋ . ⟍ . .
⟋ . . . ⟍
. \ . OH . HO . / .
. . \ . . . / . .
H . . . . . . . OH
. . H . H . .

Above is a Haworth projection of the monosaccharide α-D-lyxose. Which one of the following Haworth projections is of the monosaccharide α-L-lyxose?

 

Matching Common Polysaccharides to Descriptions

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Match each of the following polysaccharides with their corresponding descriptions.
Note: Each choice will be used exactly once.

Your Choice Prompt
Drop Your Choice Here 1. amylose
Drop Your Choice Here 2. amylopectin
Drop Your Choice Here 3. glycogen
Drop Your Choice Here 4. chitin
Drop Your Choice Here 5. cellulose

Drag one of the choices below:

  • A. unbranched energy storage in plants
  • B. carbohydrate polymer that used for structural purposes by some animals
  • C. highly branched polymer of α-linked glucose units found in animals
  • D. plant molecule composed of linear chains of α-(1,4) D-glucose residues connected through α-(1,6) linkages
  • E. polymer of β-linked glucose units found in plants
 

Identifying Characteristics of Common Polysaccharides

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Which one of the following polysaccharides correspond to the description 'structural form of glucose in some animals'.

 

Determining Monosaccharide Classes from Fischer Projections

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Fischer classification problem

. . CH2OH
. ==O 
H . . . . OH
. . . .
H . . . . OH
. . . .
HO . . . . H
. . . .
. . CH2OH

The diagram above shows a Fischer projection of an unnamed monosaccharide.
Your task is to classify the sugar based on the provided categorizations below. Carefully analyze the structure and check the three categorizations that apply.
Instructions:

  • You are required to select exactly three (3) boxes.
  • Selecting fewer or more than three boxes will be marked as incorrect.
  • No partial credit will be awarded.
 

Determining Monosaccharide Classes from Haworth Projections

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Haworth classification problem

H . . .  O  . . . OH
. . ⟋ . ⟍ . .
⟋ . . . ⟍
. \ . OH . H . / .
. . \ . . . / . .
CH2OH . . . . . . . CH2OH
. . H . HO . .

The diagram above shows a Haworth projection of an unnamed monosaccharide.
Your task is to classify the sugar based on the provided categorizations below. Carefully analyze the structure and check the five categorizations that apply.
Instructions:

  • You are required to select exactly five (5) boxes.
  • Selecting fewer or more than five boxes will be marked as incorrect.
  • No partial credit will be awarded.
 

Determining Conversions Between Fischer and Haworth Projections

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D-allo-2-heptulose⟶α-D-allo-2-heptulose

. . CH2OH
. ==O 
H . . . . OH
. . . .
H . . . . OH
. . . .
H . . . . OH
. . . .
H . . . . OH
. . . .
. . CH2OH
Above is a Fischer projection of the monosaccharide D-allo-2-heptulose. Which one of the following Haworth projections is of the monosaccharide α-D-allo-2-heptulose?
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