Humans lack the enzyme to break $eta$-1,4-glycosidic linkages found in cellulose.

Lactase; $eta$-1,4-glycosidic bond

It is composed of N-acetylglucosamine monomers linked by $eta$-glycosidic bonds.

Question 1

Which of the following statements best explains why glucose and galactose, despite having the same molecular formula, function differently in cells?

Accepted Answer

They differ in the orientation of a single hydroxyl group, which affects enzyme recognition and function.

Question 2

Which chemical group is responsible for making monosaccharides highly reactive and able to form hydrogen bonds with water?

Accepted Answer

Carbonyl group

Question 3

A student draws the structure of a monosaccharide and labels the carbonyl group at the end of the carbon chain. What type of sugar is this?

Accepted Answer

Aldose

Question 4

Which of the following best describes the difference between the $eta$ and $	ext{alpha}$ forms of glucose ring structures?

Accepted Answer

The position of the new hydroxyl group on carbon 1, either above ($eta$) or below ($	ext{alpha}$) the ring plane

Question 5

Which process is responsible for joining two monosaccharides to form a disaccharide, and what is released during this reaction?

Accepted Answer

Condensation (dehydration synthesis); water is released

Question 6

Why can humans digest starch but not cellulose, even though both are polymers of glucose?

Accepted Answer

Humans lack the enzyme to break $eta$-1,4-glycosidic linkages found in cellulose.

Question 7

Which of the following is a correct description of a glycosidic bond?

Accepted Answer

A covalent bond formed between hydroxyl groups of two monosaccharides during a condensation reaction.

Question 8

A patient is diagnosed with lactose intolerance. Which enzyme is deficient, and what type of glycosidic bond does this enzyme break?

Accepted Answer

Lactase; $eta$-1,4-glycosidic bond

Question 9

Which of the following best explains why polysaccharides such as starch and glycogen are effective for energy storage in cells?

Accepted Answer

They are highly branched, allowing rapid enzymatic hydrolysis to release glucose.

Question 10

Which structural feature of chitin makes it suitable for providing support in fungal cell walls and arthropod exoskeletons?

Accepted Answer

It is composed of N-acetylglucosamine monomers linked by $eta$-glycosidic bonds.

Question 11

A scientist discovers a carbohydrate with the formula $C_5H_{10}O_5$. Which type of monosaccharide is this most likely to be?

Accepted Answer

Pentose

Question 12

Which of the following statements about glycosidic linkages is TRUE?

Accepted Answer

They can form between different hydroxyl groups, leading to structural diversity in polysaccharides.

Question 13

Which property of carbohydrates allows them to act as cell identity markers on the surface of cells?

Accepted Answer

Their ability to form glycosidic bonds with proteins and lipids, creating glycosylated molecules.

Question 14

Which of the following is a correct example of a disaccharide and its monomer components?

Accepted Answer

Lactose: glucose + galactose

Question 15

During the hydrolysis of a polysaccharide, which of the following occurs?

Accepted Answer

A water molecule is added, breaking a glycosidic bond.

Question 16

Which of the following best describes the difference in digestibility between maltose and lactose?

Accepted Answer

They require different enzymes because they have different glycosidic linkages.

Question 17

Which of the following is NOT a function of carbohydrates in biological systems?

Accepted Answer

Catalyzing chemical reactions as enzymes

Question 18

A researcher is studying a polysaccharide that is highly branched and found in animal cells. Which polysaccharide is this most likely to be?

Accepted Answer

Glycogen

Question 19

Which of the following equations correctly represents the general formula for a monosaccharide?

Accepted Answer

$C_nH_{2n}O_n$

Question 20

Which feature of polysaccharides like cellulose allows them to provide structural support in plant cell walls?

Accepted Answer

The presence of $eta$-1,4-glycosidic linkages that form straight, rigid fibers.

Carbohydrates: Structure, Function, and Biological Importance

Study Guide - Practice Questions