Q: Given the following wedge-dash structure, which is the correct Fischer projection? Wedge-dash: H | HO–C–H | CHO Choose the correct Fischer projection.

$$\begin{array}{c} \text{CHO} \\ | \\ \text{HO–C–H} \\ | \\ \text{H} \end{array}$$

Q: Which of the following is the correct Fischer projection for D-glyceraldehyde?

$$\begin{array}{c} \text{CHO} \\ | \\ \text{H–C–OH} \\ | \\ \text{CH}_2\text{OH} \end{array}$$

Q: Which group is always placed at the top of a Fischer projection for an aldose sugar?

The aldehyde group ($$\text{CHO})$$

Question 1

Which of the following statements about Fischer projections is CORRECT?

Accepted Answer

Horizontal lines represent bonds coming out of the plane of the paper toward the viewer.

Question 2

When drawing a Fischer projection of a monosaccharide, where should the aldehyde or ketone group always be placed?

Accepted Answer

At the top of the projection

Question 3

Given the following wedge-dash structure, which is the correct Fischer projection?

Wedge-dash:

H
    |
HO–C–H
    |
   CHO

Choose the correct Fischer projection.

Accepted Answer

$$\begin{array}{c} 	ext{CHO} \ | \ 	ext{HO–C–H} \ | \ 	ext{H} \end{array}$$

Question 4

Which of the following best describes the relationship between a wedge-dash structure and its Fischer projection?

Accepted Answer

Wedge-dash structures and Fischer projections both show 3D orientation, but Fischer projections use a specific convention for chiral centers.

Question 5

In a Fischer projection, what do the dashed wedges in a wedge-dash structure correspond to?

Accepted Answer

Vertical lines

Question 6

A student is converting a wedge-dash structure to a Fischer projection. Which of the following is a common mistake?

Accepted Answer

Switching the horizontal and vertical lines, so that groups that should be coming out of the plane are drawn as going into the plane

Question 7

Which of the following is TRUE about the representation of chiral centers in Fischer projections?

Accepted Answer

Chiral centers are always represented by a cross, with four groups attached.

Question 8

If a Fischer projection of a sugar has the –OH group on the right at the chiral center furthest from the carbonyl group, what is the configuration (D or L)?

Accepted Answer

D

Question 9

Which of the following best explains why Fischer projections are useful for representing monosaccharides?

Accepted Answer

They allow for easy comparison of stereochemistry at multiple chiral centers.

Question 10

A chemist is analyzing a Fischer projection and wants to convert it to a wedge-dash structure. Which of the following steps is CORRECT?

Accepted Answer

Draw the horizontal groups as coming out of the plane and the vertical groups as going into the plane.

Question 11

Which of the following is the correct Fischer projection for D-glyceraldehyde?

Accepted Answer

$$\begin{array}{c} 	ext{CHO} \ | \ 	ext{H–C–OH} \ | \ 	ext{CH}_2	ext{OH} \end{array}$$

Question 12

Which group is always placed at the top of a Fischer projection for an aldose sugar?

Accepted Answer

The aldehyde group ($$	ext{CHO})$$

Question 13

Which of the following is a key difference between a Fischer projection and a wedge-dash structure?

Accepted Answer

Fischer projections show the molecule in a planar form, while wedge-dash structures show 3D geometry.

Question 14

A student draws a Fischer projection with the following arrangement:

$$\begin{array}{c} 	ext{CHO} \ | \ 	ext{HO–C–H} \ | \ 	ext{CH}_2	ext{OH} \end{array}$$

What is the configuration at the chiral center?

Accepted Answer

L

Fischer Projections and Monosaccharide Representation

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