Question 1

Which functional group on a monosaccharide reacts with the C1 aldehyde group to form a cyclic hemiacetal in aqueous solution?

Accepted Answer

The C5 hydroxyl group

Question 2

What is the relationship between the $$9-$$anomer and the $$9-$$anomer of a monosaccharide?

Accepted Answer

They are epimers, differing at the anomeric carbon

Question 3

In the Haworth projection of $$9-D-$$glucose, which group is drawn down at the anomeric carbon for the $$9-$$anomer?

Accepted Answer

The -OH group

Question 4

Which of the following best describes the process of cyclization of D-glucose in aqueous solution?

Accepted Answer

The C5 hydroxyl group attacks the C1 aldehyde, forming a six-membered ring

Question 5

When converting a Fischer projection of D-glucose to a Haworth projection, what is the correct orientation for groups on the right side of the Fischer projection?

Accepted Answer

They are drawn down in the Haworth projection

Question 6

Which statement is TRUE regarding the formation of the $$9-$$anomer of D-glucose?

Accepted Answer

The -OH group on the anomeric carbon is trans to the CH$$_2OH $$group

Question 7

D-ribose is an important sugar in DNA. In its cyclic form, what type of ring does it most commonly form?

Accepted Answer

A five-membered furanose ring

Question 8

Which of the following steps is NOT part of converting a Fischer projection to a Haworth projection for a hexose?

Accepted Answer

Oxidizing the aldehyde group to a carboxylic acid

Question 9

A student draws the Haworth projection of $$9-D-$$glucose with all -OH groups on the same side of the ring. What is the most likely error?

Accepted Answer

They did not correctly translate the right/left positions from the Fischer projection

Question 10

Which of the following best explains why D-glucose forms a six-membered ring in solution?

Accepted Answer

The C5 hydroxyl group is ideally positioned to react with the C1 aldehyde group

Question 11

Which of the following is the correct sequence of steps to draw a Haworth projection from a Fischer projection?

Accepted Answer

Number the carbons, rotate the Fischer projection, close the ring, assign up/down positions

Question 12

If the -OH group on the anomeric carbon is on the same side as the CH$$_2OH $$group in a Haworth projection, which anomer is it?

Accepted Answer

$$\beta-$$anomer

Question 13

Which of the following best describes an epimer?

Accepted Answer

Two sugars that differ in configuration at only one specific carbon

Question 14

A patient with a genetic disorder cannot convert D-glucose to its cyclic form. Which functional group is most likely defective?

Accepted Answer

The C5 hydroxyl group

Question 15

Which of the following is TRUE about the Haworth projection of D-glucose?

Accepted Answer

The CH$$_2OH $$group is always drawn above the ring for D-sugars

Question 16

Which of the following best explains why D-ribose forms a five-membered ring in solution?

Accepted Answer

The C4 hydroxyl group reacts with the C1 aldehyde group

Cyclic Structures of Monosaccharides: Formation and Haworth Projections

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