Question 1

Which of the following best describes a glycosidic bond?

Accepted Answer

A bond formed by the elimination of water between the anomeric carbon of a cyclic saccharide and the hydroxyl group of another compound.

Question 2

Which of the following is a correct general formula for a monosaccharide?

Accepted Answer

$$ (CH_2O)_n $$ where $$ n \geq 3 $$

Question 3

Which of the following statements about D- and L- enantiomers of monosaccharides is TRUE?

Accepted Answer

They are non-superimposable mirror images of each other.

Question 4

Which of the following is a function of glycosaminoglycans in the human body?

Accepted Answer

They act as biological lubricants in synovial fluids.

Question 5

Which of the following best explains why branching in glycogen is biologically significant?

Accepted Answer

It increases the number of non-reducing ends, allowing for rapid release of glucose units during energy demand.

Question 6

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

Accepted Answer

A sugar that has a free anomeric carbon capable of acting as a reducing agent.

Question 7

Which of the following is a correct statement about cellulose?

Accepted Answer

It is a linear homopolymer of $$ \beta -$$glucose connected by $$ \beta (1 \rightarrow 4) $$ linkages.

Question 8

Which of the following modifications converts glucose to sorbitol?

Accepted Answer

Reduction of the aldehyde group to a primary alcohol.

Question 9

Which of the following best describes the difference between an epimer and an anomer?

Accepted Answer

Epimers differ at one chiral center other than the anomeric carbon, while anomers differ at the anomeric carbon.

Question 10

Which of the following is a correct representation of the glycosidic linkage in sucrose?

Accepted Answer

$$ \alpha -D-$$Glcp(1 \rightarrow 2)$$ \beta -D-$$Fruf

Question 11

Which of the following statements about glycoproteins is TRUE?

Accepted Answer

They can have oligosaccharide chains covalently attached to asparagine (N-linked) or serine/threonine (O-linked) residues.

Question 12

Which of the following is a correct statement about the action of the influenza virus neuraminidase?

Accepted Answer

It cleaves sialic acid residues from the ends of N-linked oligosaccharide chains, facilitating virus release.

Question 13

Which of the following best explains why the formation of glycosidic bonds in disaccharides is not thermodynamically favored?

Accepted Answer

The standard free energy change $$ (\Delta G^\circ) $$ for glycosidic bond formation is positive.

Question 14

Which of the following is a distinguishing feature of peptidoglycan in bacterial cell walls?

Accepted Answer

It consists of alternating copolymers of N-acetylglucosamine and N-acetylmuramic acid crosslinked by short peptides.

Question 15

Which of the following is a correct statement about the ABO blood group antigens?

Accepted Answer

They are O-linked glycoproteins with different terminal sugar residues.

Question 16

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

Accepted Answer

A polysaccharide composed of only one type of monosaccharide.

Question 17

Which of the following is a correct statement about the secondary structure of amylose?

Accepted Answer

It forms a helical structure stabilized by hydrogen bonds.

Question 18

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

Accepted Answer

A monosaccharide that has been oxidized at the C1 carbon to yield an aldonic acid.

Question 19

Which of the following best describes the role of UDP-galactose in lactose biosynthesis?

Accepted Answer

It acts as an activated form of galactose, enabling the formation of the glycosidic bond with glucose.

Carbohydrates: Structure, Classification, and Biological Roles

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