Question 1

Which of the following statements best describes the difference between aldoses and ketoses in monosaccharides?

Accepted Answer

Aldoses have a carbonyl group at the end of the carbon chain, while ketoses have it at an internal carbon.

Question 2

Which equation represents the general formula for many monosaccharides?

Accepted Answer

$$\mathrm{C}_n(\mathrm{H}_2\mathrm{O})_n$$

Question 3

Which of the following is NOT a function of carbohydrates in living organisms?

Accepted Answer

Catalysis of biochemical reactions

Question 4

Glucose can react with Cu$$^{2+}$$ ions in a laboratory test. What property of glucose allows this reaction?

Accepted Answer

Glucose is a reducing sugar due to its equilibrium with the open-chain aldehyde form.

Question 5

Which of the following best describes an epimer?

Accepted Answer

Two monosaccharides that differ only in the configuration around one carbon atom.

Question 6

Which linkage is found at the branch points of glycogen?

Accepted Answer

$$\alpha-1$$,6 glycosidic bond

Question 7

Which of the following polysaccharides is a major structural component of plant cell walls?

Accepted Answer

Cellulose

Question 8

What is the main difference between amylose and amylopectin?

Accepted Answer

Amylose is unbranched, while amylopectin is branched.

Question 9

Which of the following is a correct description of the chair conformation of glucose?

Accepted Answer

It is more stable than the boat conformation due to reduced steric crowding.

Question 10

Which of the following is a consequence of lactose intolerance in humans?

Accepted Answer

Bacteria in the gut degrade lactose to methane, hydrogen, and lactic acid, causing flatulence and diarrhea.

Question 11

Which of the following best describes the role of glycosaminoglycans (GAGs) in animal tissues?

Accepted Answer

They are major components of the extracellular matrix, providing structural support.

Question 12

Which of the following is true about the glycoprotein erythropoietin (EPO)?

Accepted Answer

It contains oligosaccharide chains that protect the protein from degradation.

Question 13

Which of the following is a correct statement about the formation of N-glycosidic bonds?

Accepted Answer

They are formed between the anomeric carbon atom of a monosaccharide and a nitrogen atom of an amino group.

Question 14

Which of the following is a correct description of the Haworth projection?

Accepted Answer

It is a two-dimensional representation of the three-dimensional ring structure of monosaccharides.

Question 15

Which of the following best explains why most naturally occurring sugars are D isomers?

Accepted Answer

Enzymes in living organisms are stereospecific and preferentially synthesize D isomers.

Question 16

Which of the following is a correct description of the sugar code?

Accepted Answer

Oligosaccharide chains are complex and diverse, allowing for specific protein-protein and cell-cell communication.

Question 17

Which of the following is a correct statement about the structure of cellulose?

Accepted Answer

Cellulose is a linear polysaccharide of glucose with $$\beta-1$$,4 bonds forming extended chains.

Question 18

Which of the following best describes the function of oligosaccharides attached to proteins?

Accepted Answer

They can carry information relevant for protein-protein or cell-cell communication.

Question 19

Which of the following is a correct description of the equilibrium between open and ring forms of glucose?

Accepted Answer

Ring formation is reversible and happens spontaneously, allowing glucose to behave like an aldehyde.

Carbohydrates: Structure, Diversity, and Biological Roles

Guida di studio - Domande di pratica