Question 1

Which functional group is present in all carbohydrates and is responsible for their classification as aldoses or ketoses?

Accepted Answer

Carbonyl group

Question 2

A carbohydrate with the formula $$C_6H_{12}O_6$ and a carbonyl group at the end of its chain is classified as which type of sugar?

Accepted Answer

Aldose

Question 3

How many stereoisomers are possible for an aldohexose, given that it has 4 chiral centers?

Accepted Answer

$$2^4 = 16$

Question 4

Which term describes two sugars that differ only at one chiral center?

Accepted Answer

Epimers

Question 5

D-glucose and D-mannose are epimers at which carbon atom?

Accepted Answer

C-2

Question 6

What is the process called when a monosaccharide forms a ring structure by reaction between its carbonyl group and a hydroxyl group?

Accepted Answer

Cyclization

Question 7

Which carbon becomes the new chiral center (anomeric carbon) during the cyclization of glucose?

Accepted Answer

C-1

Question 8

What is the difference between α and β anomers of D-glucose?

Accepted Answer

The position of the hydroxyl group on the anomeric carbon relative to the CH$$_2OH $$group

Question 9

Which type of glycosidic bond is found in the main chain of amylose?

Accepted Answer

$$\alpha 1 \rightarrow 4$$

Question 10

Cellulose is a linear homopolysaccharide of glucose. Which glycosidic linkage is characteristic of cellulose?

Accepted Answer

$$\beta 1 \rightarrow 4$$

Question 11

Which property distinguishes diastereomers from enantiomers?

Accepted Answer

Diastereomers have different physical properties, while enantiomers have identical physical properties except for optical activity.

Question 12

Which of the following statements about mutarotation is correct?

Accepted Answer

Mutarotation is the change in optical rotation as equilibrium is reached between α and β anomers and the linear form of a sugar in solution.

Question 13

Which enzyme is required to hydrolyze the $$\beta 1 \rightarrow 4$$ linkages in cellulose?

Accepted Answer

Cellulase

Question 14

Which of the following is a branched homopolysaccharide of glucose found in animals?

Accepted Answer

Glycogen

Question 15

A glycosidic bond formed between two anomeric carbons results in which type of disaccharide?

Accepted Answer

Non-reducing disaccharide

Question 16

Which structural feature of chitin makes it similar to cellulose?

Accepted Answer

Both are linear polymers with $$\beta 1 \rightarrow 4$$ linkages

Question 17

Which of the following is a heteropolysaccharide used in laboratory gels for DNA electrophoresis?

Accepted Answer

Agarose

Question 18

Which type of glycosidic bond connects the carbohydrate to the amino acid serine in O-linked glycoproteins?

Accepted Answer

Glycosidic bond to the hydroxyl group of serine

Question 19

Which carbohydrate derivative is commonly used as a dietary supplement and forms a linker between carbohydrates and proteins or lipids?

Accepted Answer

Glucosamine

Question 20

Which of the following best describes the role of polysaccharides in the extracellular matrix (ECM)?

Accepted Answer

They provide strength, elasticity, and act as a physical barrier in tissues.

Carbohydrates: Structure, Stereochemistry, and Biological Roles

Guida di studio - Domande di pratica