Question 1

Which of the following statements best describes a chiral carbon atom?

Accepted Answer

A carbon atom bonded to four different groups.

Question 2

Which of the following is a correct Fischer projection for a D-isomer of a monosaccharide?

Accepted Answer

The $$-OH$$ group on the chiral carbon farthest from the carbonyl is on the right.

Question 3

Which of the following best describes an enantiomer?

Accepted Answer

Molecules that are non-superimposable mirror images of each other.

Question 4

A patient is given a drug that is a racemic mixture. What does this mean?

Accepted Answer

The drug contains a 50:50 mixture of two enantiomers.

Question 5

Which of the following is true about monosaccharides?

Accepted Answer

They can be classified as either aldoses or ketoses.

Question 6

In a Fischer projection, which group is always placed at the top?

Accepted Answer

The most highly oxidized carbon, usually the carbonyl group.

Question 7

Which of the following is an example of a structural isomer?

Accepted Answer

Two molecules with the same molecular formula but different connectivity.

Question 8

Which statement about enantiomers in biological systems is correct?

Accepted Answer

Only one enantiomer may fit properly into an enzyme or receptor.

Question 9

A monosaccharide with five carbon atoms and an aldehyde group is classified as:

Accepted Answer

An aldopentose

Question 10

Which of the following pairs are epimers?

Accepted Answer

Two monosaccharides that differ at only one chiral center.

Question 11

How many chiral centers are present in the Fischer projection of D-glucose?

Accepted Answer

4

Question 12

Which of the following is true about the D and L notation for monosaccharides?

Accepted Answer

It refers to the position of the $$-OH$$ group on the chiral carbon farthest from the carbonyl group.

Question 13

Which of the following is NOT a property of chiral molecules?

Accepted Answer

They are always superimposable on their mirror image.

Question 14

Which of the following best describes a Fischer projection?

Accepted Answer

A two-dimensional representation where horizontal lines represent bonds coming forward and vertical lines represent bonds going back.

Question 15

Which of the following is a ketose?

Accepted Answer

A monosaccharide with a carbonyl group on an internal carbon atom.

Question 16

Which of the following is true about stereoisomers?

Accepted Answer

They have identical molecular formulas and connectivity but differ in spatial arrangement.

Question 17

Which of the following is a real-world example of chirality affecting drug action?

Accepted Answer

Only L-dopa is effective in treating Parkinson's disease, while D-dopa is not.

Question 18

In the Fischer projection of mannose, the $$-OH$$ group on the chiral carbon farthest from the carbonyl is on the left. What is the configuration?

Accepted Answer

L-isomer

Question 19

Which of the following is true about achiral molecules?

Accepted Answer

Their mirror images can be superimposed.

Question 20

Which of the following best describes the difference between an aldose and a ketose?

Accepted Answer

An aldose has a carbonyl group at the end of the carbon chain, while a ketose has it on an internal carbon atom.

Carbohydrates: Structure, Isomerism, and Biological Relevance

Study Guide - Practice Questions