$$\begin{array}{c}CHO\\H-C-OH\\CH_2OH\end{array}$$

Question 1

Which of the following is a bioinorganic substance found in the human body, and what is its approximate percentage by mass?

Accepted Answer

Water, about 70%

Question 2

Which functional group is present in glucose but not in fructose?

Accepted Answer

Aldehyde group

Question 3

Which of the following best describes the relationship between D-glucose and D-galactose?

Accepted Answer

They are diastereomers

Question 4

Which carbon atom in D-glucose becomes the anomeric carbon when the molecule cyclizes to form a pyranose ring?

Accepted Answer

$$C_1$$

Question 5

What is the main structural difference between an alpha ($$\alpha) $$and beta ($$\beta) $$anomer of D-glucose?

Accepted Answer

The position of the $$-OH$$ group at the anomeric carbon ($$C_1)$$

Question 6

Which of the following molecules is a furanose ring structure?

Accepted Answer

$$\alpha-D-$$Fructose

Question 7

Which of the following statements about enantiomers is correct?

Accepted Answer

They are nonsuperimposable mirror images

Question 8

Which of the following best describes the oxidation of a primary alcohol?

Accepted Answer

It forms an aldehyde, which can further oxidize to a carboxylic acid

Question 9

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

Accepted Answer

$$\begin{array}{c}CHO\H-C-OH\CH_2OH\end{array}$$

Question 10

Which of the following best explains why D-glucose and D-fructose are considered structural isomers?

Accepted Answer

They have the same molecular formula but different connectivity of atoms

Question 11

Which of the following is a correct statement about the difference between D-ribose and 2-deoxy-D-ribose?

Accepted Answer

2-deoxy-D-ribose lacks an oxygen atom at the 2' position compared to D-ribose

Question 12

Which of the following best describes the relationship between the two molecules shown below?

$$\begin{array}{c}CHO\H-C-OH\HO-C-H\CH_2OH\end{array}$$ and $$\begin{array}{c}CHO\HO-C-H\H-C-OH\CH_2OH\end{array}$$

Accepted Answer

They are diastereomers

Question 13

Which of the following is true about the formation of a hemiacetal ring in glucose?

Accepted Answer

It involves the reaction of the aldehyde group at $$C_1$$ with the hydroxyl group at $$C_5$$

Question 14

Which of the following best describes the difference between a pyranose and a furanose ring?

Accepted Answer

A pyranose ring has six atoms, while a furanose ring has five atoms

Question 15

Which of the following is a correct statement about the D and L notation in sugars?

Accepted Answer

D and L refer to the configuration around the chiral carbon farthest from the carbonyl group

Question 16

Which of the following best describes the process shown in the oxidation of D-glucose to D-gluconic acid?

Accepted Answer

The aldehyde group at $$C_1 is $$oxidized to a carboxylic acid

Question 17

Which of the following is a correct statement about stereoisomers?

Accepted Answer

They have the same connectivity but differ in spatial arrangement

Question 18

Which of the following best describes the relationship between D-glucose and L-glucose?

Accepted Answer

They are enantiomers

Carbohydrates: Structure, Isomerism, and Biochemical Significance

Study Guide - Practice Questions