Question 1

Which of the following best describes the difference between an aldosugar and a ketosugar?

Accepted Answer

Aldosugars have a terminal carbonyl group, while ketosugars have an internal carbonyl group.

Question 2

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

Accepted Answer

$$C_nH_{2n}O_n$$

Question 3

Which enzyme is responsible for breaking down starch into its monomeric units in the human digestive system?

Accepted Answer

Amylase

Question 4

Which of the following statements about cellulose is TRUE?

Accepted Answer

It is composed of β-D-glucose units linked by β(1→4) bonds.

Question 5

Which of the following best explains why glycogen is more highly branched than amylopectin?

Accepted Answer

Glycogen has branches every 8–10 glucose units, while amylopectin branches every 12–25 units.

Question 6

Which of the following disaccharides is composed of one glucose and one galactose molecule joined by a β glycosidic bond?

Accepted Answer

Lactose

Question 7

A patient is diagnosed with a deficiency in the enzyme maltase. Which dietary carbohydrate would they have the most difficulty digesting?

Accepted Answer

Maltose

Question 8

Which of the following best describes the structural difference between starch and cellulose?

Accepted Answer

Starch contains α(1→4) glycosidic bonds, while cellulose contains β(1→4) bonds.

Question 9

Which of the following is a correct statement about chitin?

Accepted Answer

It is composed of N-acetylglucosamine units joined by β(1→4) bonds.

Question 10

Which of the following best explains why mammals cannot digest cellulose?

Accepted Answer

Mammals lack the enzyme to hydrolyze β(1→4) glycosidic bonds.

Question 11

Which of the following is a function of oligosaccharides attached to cell surface proteins?

Accepted Answer

Cellular recognition

Question 12

Which of the following best describes the difference in structure between amylose and amylopectin?

Accepted Answer

Amylose is unbranched, while amylopectin is branched.

Question 13

Which of the following is a correct pairing of polysaccharide and its primary biological role?

Accepted Answer

Starch – energy storage in plants

Question 14

Which of the following best explains why α and β glycosidic bonds result in different polysaccharide structures?

Accepted Answer

α bonds create loose, helical structures, while β bonds create rigid, linear structures.

Question 15

A scientist isolates a polysaccharide from a bacterial cell wall that contains alternating units of N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc). Which polysaccharide has she most likely isolated?

Accepted Answer

Peptidoglycan

Question 16

Which of the following is a similarity between polysaccharides, proteins, and nucleic acids?

Accepted Answer

They are all composed of repeating monomeric units.

Question 17

Which of the following best describes the role of amyloplasts in plant cells?

Accepted Answer

They are specialized for starch storage.

Question 18

Which of the following is the correct chemical formula for D-glucose?

Accepted Answer

$$C_6H_{12}O_6$

Question 19

Which of the following best explains why cellulose forms microfibrils in plant cell walls?

Accepted Answer

Cellulose chains are linear and aggregate via hydrogen bonding.

Question 20

A mutation in a plant prevents the formation of α(1→6) glycosidic bonds. Which of the following would be most directly affected?

Accepted Answer

The branching of amylopectin in starch

Polysaccharides: Structure, Function, and Classification in Cell Biology

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