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9: Carbohydrates

Carbohydrate structure, glycosidic bonds, biological roles.

LibreTexts reference: Carbohydrates

Fischer Projections of D and L from Monosaccharides

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D-glycero-D-gulo-heptose⟶L-glycero-L-gulo-heptose

H  .  O
. \   // .
. . C . .
H . . . . OH
. . . .
H . . . . OH
. . . .
HO . . . . H
. . . .
H . . . . OH
. . . .
H . . . . OH
. . . .
. . CH2OH

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

 

Haworth Projections of D and L from Monosaccharides

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α-D-talose

HO . . . CH2OH . . . . . H
. . . .         . . . .
. . / . . . O . .
. . / . H . . . \ . .
/ . . Haworth . . \
. \ . . . . / .
. \ . OH . HO . / .
H . . \ . . . / . . OH
. . . . . . . . .
. . . H . H . . .

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

 

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

Drag one of the choices below:

  • A. plant molecule composed of linear chains of α-(1,4) D-glucose residues connected through α-(1,6) linkages
  • B. structural material in arthropods and fungi
  • C. storage form of glucose in animals
  • D. also know as resistant starch, because it has no branches and it is resistant to digestion
  • E. major structural component of cell walls
 

Characteristics of Common Polysaccharides

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Which one of the following polysaccharides correspond to the description 'highly branched energy storage in animals'.

 

Classify the Fischer Projection of a Monosaccharide

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Fischer classification problem

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

Classify the Haworth Projection of a Monosaccharide

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Haworth classification problem

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

Convert Betweeen Fischer and Haworth Projection

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α-D-idose⟶D-idose

HO . . . CH2OH . . . . . H
. . . .         . . . .
. . / . . . O . .
. . / . H . . . \ . .
/ . . Haworth . . \
. \ . . . . / .
. \ . H . HO . / .
H . . \ . . . / . . OH
. . . . . . . . .
. . . OH . H . . .
Above is a Haworth projection of the monosaccharide α-D-idose. Which one of the following Fischer projections is of the monosaccharide D-idose?