Question 1

Only one of the following molecules is a naturally occurring sugar.Which statement is a reason that only one of the sugars is naturally occurring? 
A) Naturally occurring sugars do not have multiple hydroxyl groups on a single carbon.
B) D-sugars are much more common than L-sugars.
C) Naturally occurring sugars are polyhydroxylated.
D) Naturally occurring sugars contain a carbonyl.
E) All of the above are true statements.

Accepted Answer

E

Question 2

Which statement BEST describes how brushing your teeth prevents cavities?
A) Toothpaste stops the metabolism of glucose.
B) Toothpaste neutralizes lactic acid.
C) Brushing removes sugars.
D) Brushing removes anaerobic bacteria.
E) Toothpaste increases pH in the mouth.

Accepted Answer

Brushing removes sugars that feed bacteria, which produce acids that cause cavities.

Question 3

What is produced by cellular respiration?
A) oxygen
B) sugars
C) carbon dioxide, water, and energy
D) oxygen and energy
E) oxygen, sugars, and energy

Accepted Answer

Cellular respiration converts glucose and oxygen into carbon dioxide, water, and energy (in the form of ATP), making option C the correct answer. Oxygen is consumed, not produced, and sugars are the input, not the output.

Question 4

Which glycosidic linkage does the sugar shown below contain? 
A) β-(2→4)
B) α-(1→4)
C) β-(1→4)
D) α-(2→4)
E) α-(2→6)

Accepted Answer

The answer of Which glycosidic linkage does the sugar shown...

Question 5

Below is the open-chain form of fructose, followed by several cyclic monosaccharides.Choose the cyclic monosaccharides that are the ring form of fructose. 
A) Only structure II is D-fructose.
B) Only structure III is D-fructose.
C) Both structures I and II are D-fructose.
D) Both structure III and IV are D-fructose.
E) All of these structures are D-fructose.

Accepted Answer

The answer of Below is the open-chain form of fructose,...

Question 6

Photosynthesis and cellular respiration together form___________.
A) metabolism
B) catabolism and anabolism
C) energy and matter
D) a biochemical pathway
E) the carbon cycle

Accepted Answer

Photosynthesis and cellular respiration are key processes in the carbon cycle, where photosynthesis captures carbon dioxide to produce glucose and oxygen, and cellular respiration uses glucose and oxygen to release energy, carbon dioxide, and water.

Question 7

Which of the following features is NOT shared by all monosaccharides?
A) Monosaccharides cannot be hydrolyzed into simpler carbohydrates.
B) Monosaccharides all contain six carbons.
C) Monosaccharides have an aldehyde or a ketone.
D) Monosaccharides contain two or more alcohols.
E) Monosaccharides are polyhydroxylated.

Accepted Answer

Monosaccharides vary in the number of carbon atoms they contain, ranging from three to seven carbons, not all have six carbons.

Question 8

Type _____ blood is the universal donor, whereas type _____ is the universal recipient.
A) O; AB
B) AB; O
C) A; B
D) B; A
E) O; A or B

Accepted Answer

Type O blood is considered the universal donor because it can be donated to individuals of any blood type, and type AB is the universal recipient because individuals with this blood type can receive blood from any other type.

Question 9

Which of the following statements related to the formation of dental caries is FALSE?
A) Anaerobic bacteria produce lactic acid.
B) Anaerobic bacteria convert glucose into carbon dioxide and water.
C) Lactic acid reduces the pH of the environment of the tooth enamel to pH 4-5.
D) Tooth enamel dissolves in a pH 4-5 environment.
E) Brushing removes sugars from the teeth.

Accepted Answer

Anaerobic bacteria involved in the formation of dental caries primarily convert glucose into lactic acid, not carbon dioxide and water. This lactic acid production is what leads to the lowering of pH and subsequent tooth enamel dissolution.

Question 10

The Fischer projection for fructose is shown below.Which functional group(s)does fructose contain? 
A) an aldehyde only
B) hydroxyl groups only
C) hydroxyl groups and an alkene
D) hydroxyl groups and a ketone
E) hydroxyl groups and an aldehyde

Accepted Answer

The answer of The Fischer projection for fructose is shown...

Question 11

Which of the following types of carbohydrates can be hydrolyzed to give smaller molecules? I.Monosaccharides
II)Disaccharides
III)Oligosaccharides
IV)Polysaccharides
A) I only
B) II and IV only
C) III only
D) I and II only
E) II, III, and IV

Accepted Answer

Monosaccharides cannot be hydrolyzed further as they are already the simplest form of carbohydrates. Disaccharides, oligosaccharides, and polysaccharides can be hydrolyzed to give smaller molecules.

Question 12

Do you expect monosaccharides to be soluble in water?
A) Yes, because monosaccharides are acidic.
B) No, because monosaccharides have too many carbons to be soluble.
C) Yes, because monosaccharides can hydrogen bond with water.
D) No, because monosaccharides cannot form intermolecular attractive forces with water.
E) Yes, because monosaccharides are basic.

Accepted Answer

Monosaccharides are soluble in water primarily because they can form hydrogen bonds with water molecules. This is due to the presence of hydroxyl groups (-OH) in their structure, which can interact with water, making them soluble.

Question 13

Sucrose, the disaccharide shown below, is a nonreducing sugar because 
A) it is a disaccharide.
B) ring A can open and form a carbonyl.
C) ring B can open and form a carbonyl.
D) it contains a glycosidic linkage.
E) neither ring can open.

Accepted Answer

The answer of Sucrose, the disaccharide shown below, is a...

Question 14

Which object is chiral?
A) a screw
B) a nail
C) a pencil
D) a table
E) a bed

Accepted Answer

A screw is chiral because it cannot be superimposed on its mirror image, similar to how left and right hands are mirror images but not superimposable.

Question 15

A racemic mixture is
A) a 50:50 mixture of enantiomers.
B) optically active.
C) a pure sample of a single enantiomer.
D) dextrorotatory.
E) indicated by the IUPAC prefix R.

Accepted Answer

A racemic mixture is a 50:50 mixture of two enantiomers, which are molecules that are mirror images of each other. This mixture is not optically active because the effects of each enantiomer cancel each other out.

Question 16

In which of the following Haworth projections is the arrow pointing to the anomeric carbon? 
A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Accepted Answer

The answer of In which of the following Haworth projections...

Question 17

What is the relationship between D- and L-glucose?
A) They are identical.
B) They are constitutional isomers.
C) They are diastereomers.
D) They are enantiomers.
E) They are conformers.

Accepted Answer

D- and L-glucose are mirror images of each other but are not superimposable, making them enantiomers.

Question 18

What is the product(s)of the hydrolysis of the following sugar? 
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of What is the product(s)of the hydrolysis of...

Question 19

Which disaccharide is found in milk?
A) lactose
B) sucrose
C) cellobiose
D) maltose
E) both cellobiose and maltose

Accepted Answer

Lactose is the disaccharide found in milk, consisting of glucose and galactose units.

Question 20

Nature produces predominantly __________-carbohydrates and _______-amino acids.
A) D, D
B) D, L
C) L, D
D) L, L
E) Nature does not favor one stereoisomer over another.

Accepted Answer

Nature predominantly produces D-carbohydrates and L-amino acids. This is due to the specific enzymes in living organisms that are evolved to synthesize and metabolize these particular stereoisomers.

Quiz 14: Carbohydrates: Structure and Function

Only one of the following molecules is a naturally occurring sugar.Which statement is a reason that only one of the sugars is naturally occurring?

Which statement BEST describes how brushing your teeth prevents cavities?

What is produced by cellular respiration?

Which glycosidic linkage does the sugar shown below contain?

Below is the open-chain form of fructose, followed by several cyclic monosaccharides.Choose the cyclic monosaccharides that are the ring form of fructose.

Photosynthesis and cellular respiration together form___________.

Which of the following features is NOT shared by all monosaccharides?

Type _ blood is the universal donor, whereas type _ is the universal recipient.

Which of the following statements related to the formation of dental caries is FALSE?

The Fischer projection for fructose is shown below.Which functional group(s) does fructose contain?

Which of the following types of carbohydrates can be hydrolyzed to give smaller molecules? I.Monosaccharides II) Disaccharides III) Oligosaccharides IV) Polysaccharides

Do you expect monosaccharides to be soluble in water?

Sucrose, the disaccharide shown below, is a nonreducing sugar because

Which object is chiral?

A racemic mixture is

In which of the following Haworth projections is the arrow pointing to the anomeric carbon?

What is the relationship between D- and L-glucose?

What is the product(s) of the hydrolysis of the following sugar?

Which disaccharide is found in milk?

Nature produces predominantly ____-carbohydrates and _-amino acids.