Question 1

Which of the following best describes the general formula for carbohydrates?

Accepted Answer

$\mathrm{(C_nH_{2n}O_n)}$, where $n \geq 3$

Question 2

Which modification of a monosaccharide results in the formation of an aldonic acid?

Accepted Answer

Oxidation of the aldehyde group to a carboxylic acid

Question 3

Cellulose is composed of glucose units linked by which type of glycosidic bond?

Accepted Answer

$\beta(1 \rightarrow 4)$ glycosidic bonds

Question 4

Which of the following statements about glycosidic bonds is TRUE?

Accepted Answer

They can be formed in either the $\alpha$ or $\beta$ configuration and link monosaccharides through positions such as 1-2, 1-4, or 1-6.

Question 5

Which of the following is a function of oligosaccharides attached to proteins in eukaryotic cells?

Accepted Answer

They help define protein structure and influence protein folding.

Question 6

A patient with type O blood is considered a universal donor because:

Accepted Answer

Type O blood has an inactive glycosyltransferase enzyme, resulting in the H antigen that is not recognized as foreign by other blood types.

Question 7

Which of the following is TRUE regarding the difference between amylose and cellulose?

Accepted Answer

Amylose has $\alpha(1 \rightarrow 4)$ linkages, which are digestible by humans, while cellulose has $\beta(1 \rightarrow 4)$ linkages, which are not.

Question 8

Which of the following is a real-world consequence of bacterial biofilm formation?

Accepted Answer

Biofilms create barriers to antibiotics and can cause problems in medical devices and water pipes.

Question 9

Which of the following best describes the role of lectins in cell biology?

Accepted Answer

Lectins are proteins that bind specific carbohydrates on cell surfaces, mediating cell recognition and communication.

Question 10

Which modification produces an amino sugar?

Accepted Answer

Replacement of one or more OH groups with an amino group, sometimes acetylated

Question 11

Which of the following is TRUE about the structure of chitin?

Accepted Answer

Chitin is a polymer of N-acetylglucosamine linked by $\beta(1 \rightarrow 4)$ bonds.

Question 12

Which of the following is a correct statement about the Fischer convention for sugars?

Accepted Answer

The D-configuration is based on the arrangement of groups around the asymmetric carbon in D-glyceraldehyde.

Question 13

Which of the following is a consequence of the flexibility of oligosaccharides attached to proteins?

Accepted Answer

They can shield large portions of the protein, modifying interactions with solvent and other proteins.

Question 14

Which of the following is TRUE about the action of ricin?

Accepted Answer

Ricin inactivates ribosomes by cleaving the adenine N-glycosidic bond of the large RNA on the 60S subunit.

Question 15

Which of the following is a correct description of a deoxysugar?

Accepted Answer

A monosaccharide in which an OH group is replaced by a hydrogen atom

Question 16

Which of the following is TRUE about proteoglycans?

Accepted Answer

Proteoglycans contain a core protein and glycosaminoglycans, forming a bottle brush structure.

Question 17

Which of the following is a correct statement about the synthesis of N-linked oligosaccharides?

Accepted Answer

N-linked oligosaccharides are synthesized and added to proteins as they are being synthesized, influencing protein folding.

Question 18

Which of the following is TRUE about the antigenic determinants of ABO blood types?

Accepted Answer

Type A blood has a glycosyltransferase that adds a GalNAc to the terminal position of the H antigen.

Carbohydrates: Structure, Function, and Biological Roles

Study Guide - Practice Questions