Question 1

Which enzyme is responsible for hydrolyzing the $$\beta(1 \rightarrow 4)$$ glycosidic linkage between galactose and glucose in lactose?

Accepted Answer

Lactase

Question 2

Cellulose and amylose are both homopolysaccharides of glucose with $$1 \rightarrow 4$$ glycosidic linkages. Why is cellulose insoluble in water while amylose is water-soluble?

Accepted Answer

Cellulose forms extensive intermolecular hydrogen bonds between parallel chains, reducing its ability to interact with water.

Question 3

Which of the following best describes the structure of glycogen?

Accepted Answer

A branched glucan with $$\alpha(1 \rightarrow 4)$$ linked glucose units and $$\alpha(1 \rightarrow 6)$$ branches every 12-14 residues.

Question 4

Which glycosidic linkage is found in cellulose, making it indigestible for humans?

Accepted Answer

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

Question 5

A patient is diagnosed with lactose intolerance. Which biochemical explanation best describes their condition?

Accepted Answer

They lack the enzyme lactase, which hydrolyzes the $$\beta(1 \rightarrow 4)$$ linkage in lactose.

Question 6

Which of the following statements about glycosidic linkages is TRUE?

Accepted Answer

Glycosidases are selective for both the stereochemistry and position of the glycosidic linkage.

Question 7

Which process is used industrially to convert D-glucose to D-fructose in the production of high fructose corn syrup (HFCS)?

Accepted Answer

Isomerization by glucose isomerase

Question 8

Which of the following is a major function of glycosaminoglycans in the extracellular matrix?

Accepted Answer

Structural support and cell signaling

Question 9

Which enzyme is responsible for hydrolyzing $$\alpha(1 \rightarrow 4)$$ glycosidic linkages in amylose and amylopectin?

Accepted Answer

Amylase

Question 10

Which of the following best explains why oligosaccharides are considered 'information-dense' molecules?

Accepted Answer

They can vary in monosaccharide composition, glycosidic bond position, branching, and substituent groups.

Question 11

Which of the following is a heteropolysaccharide found in bacterial cell walls, consisting of alternating N-acetylglucosamine and N-acetylmuramic acid?

Accepted Answer

Peptidoglycan

Question 12

Which statement about the tertiary structure of polysaccharides is correct?

Accepted Answer

It describes the overall three-dimensional fold of the molecule, bringing distant parts of the chain close together.

Question 13

Which of the following is TRUE regarding the branching patterns of amylopectin and glycogen?

Accepted Answer

Glycogen has $$\alpha(1 \rightarrow 6)$$ branches every 12-14 glucose residues, while amylopectin has branches every 24-30 residues.

Question 14

Which of the following is a function of lectins in biological systems?

Accepted Answer

Reading the sugar code for cell recognition and signaling

Question 15

A scientist is analyzing a glycoprotein and finds that the attached oligosaccharide increases the protein's stability and helps in cellular recognition. What is the term for this type of molecule?

Accepted Answer

Glycoconjugate

Question 16

Which of the following enzymes is bifunctional and found in the small intestine, capable of hydrolyzing both sucrose and $$\alpha(1 \rightarrow 6)$$ linkages in amylopectin?

Accepted Answer

Sucrase-isomaltase

Question 17

Which of the following is a homopolysaccharide of D-N-acetylglucosamine with $$\beta(1 \rightarrow 4)$$ linkages, found in fungal cell walls?

Accepted Answer

Chitin

Question 18

Which of the following best describes the role of glycomics?

Accepted Answer

The study of the structure and function of glycoconjugates

Question 19

Which of the following is a reason why humans cannot digest cellulose?

Accepted Answer

Humans lack enzymes that hydrolyze $$\beta(1 \rightarrow 4)$$ glycosidic linkages between glucose units.

Question 20

Which of the following statements about the physical properties of polysaccharides is correct?

Accepted Answer

The configuration of the anomeric carbon has a major impact on the physical properties of the polymer.

Carbohydrates: Structure, Glycosidic Linkages, and Biological Roles

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