CHEM 212 Module 4 - Original Practice Exam Page 1
, CHEM 212 Module 4 - Practice Exam
Select the best answer for each item. The correct answer and rationale follow each question.
CHEM 212 Module 4 Exam | Biochemistry w/Lab | Portage Learning | Q & A | 2026/2027 Actual (PDF)
1. Which feature most directly classifies a monosaccharide as an aldose rather than a ketose?
A. It contains only hydroxyl groups and no carbonyl group.
B. It contains an aldehyde-derived carbonyl at the end of the carbon chain.
C. It contains a phosphate group on carbon 6.
D. It contains a ketone-derived carbonyl within the carbon chain.
Correct Answer: B. It contains an aldehyde-derived carbonyl at the end of the carbon chain.
Rationale: Aldoses have an aldehyde-derived carbonyl at the terminal carbon in their open-chain form, whereas ketoses
have an internal ketone carbonyl.
2. In the open-chain form of D-glucose, which carbon is the carbonyl carbon?
A. Carbon 5
B. Carbon 1
C. Carbon 2
D. Carbon 6
Correct Answer: B. Carbon 1
Rationale: Glucose is an aldohexose, so its aldehyde carbonyl is located at carbon 1.
3. In the open-chain form of fructose, the carbonyl carbon is primarily located at:
A. Carbon 2
B. Carbon 6
C. Carbon 5
D. Carbon 1
Correct Answer: A. Carbon 2
Rationale: Fructose is a ketohexose; its ketone carbonyl is at carbon 2.
4. Which statement best describes a carbohydrate in the classical empirical sense?
A. All carbohydrates are polymers of glucose.
B. All carbohydrates contain nitrogen.
C. Every carbohydrate has exactly six carbons.
D. Many simple carbohydrates approximate the formula (CH2O)n.
Correct Answer: D. Many simple carbohydrates approximate the formula (CH2O)n.
CHEM 212 Module 4 - Original Practice Exam Page 2
, Rationale: Many monosaccharides fit the approximate empirical formula (CH2O)n, although important carbohydrate
derivatives may not.
5. A six-carbon monosaccharide is called a:
A. Hexose
B. Pentose
C. Triose
D. Heptose
Correct Answer: A. Hexose
Rationale: The prefix hex- denotes six carbons.
6. A five-carbon monosaccharide is called a:
A. Octose
B. Hexose
C. Pentose
D. Tetrose
Correct Answer: C. Pentose
Rationale: The prefix pent- denotes five carbons.
7. Which pair consists entirely of hexoses?
A. Ribose and deoxyribose
B. Glyceraldehyde and fructose
C. Glucose and fructose
D. Ribose and glucose
Correct Answer: C. Glucose and fructose
Rationale: Glucose and fructose each contain six carbon atoms.
8. Which monosaccharide is an aldohexose?
A. Glucose
B. Fructose
C. Ribulose
D. Dihydroxyacetone
Correct Answer: A. Glucose
Rationale: Glucose contains six carbons and an aldehyde-derived carbonyl in its open-chain form.
9. Which monosaccharide is a ketohexose?
A. Ribose
CHEM 212 Module 4 - Original Practice Exam Page 3
, CHEM 212 Module 4 - Practice Exam
Select the best answer for each item. The correct answer and rationale follow each question.
CHEM 212 Module 4 Exam | Biochemistry w/Lab | Portage Learning | Q & A | 2026/2027 Actual (PDF)
1. Which feature most directly classifies a monosaccharide as an aldose rather than a ketose?
A. It contains only hydroxyl groups and no carbonyl group.
B. It contains an aldehyde-derived carbonyl at the end of the carbon chain.
C. It contains a phosphate group on carbon 6.
D. It contains a ketone-derived carbonyl within the carbon chain.
Correct Answer: B. It contains an aldehyde-derived carbonyl at the end of the carbon chain.
Rationale: Aldoses have an aldehyde-derived carbonyl at the terminal carbon in their open-chain form, whereas ketoses
have an internal ketone carbonyl.
2. In the open-chain form of D-glucose, which carbon is the carbonyl carbon?
A. Carbon 5
B. Carbon 1
C. Carbon 2
D. Carbon 6
Correct Answer: B. Carbon 1
Rationale: Glucose is an aldohexose, so its aldehyde carbonyl is located at carbon 1.
3. In the open-chain form of fructose, the carbonyl carbon is primarily located at:
A. Carbon 2
B. Carbon 6
C. Carbon 5
D. Carbon 1
Correct Answer: A. Carbon 2
Rationale: Fructose is a ketohexose; its ketone carbonyl is at carbon 2.
4. Which statement best describes a carbohydrate in the classical empirical sense?
A. All carbohydrates are polymers of glucose.
B. All carbohydrates contain nitrogen.
C. Every carbohydrate has exactly six carbons.
D. Many simple carbohydrates approximate the formula (CH2O)n.
Correct Answer: D. Many simple carbohydrates approximate the formula (CH2O)n.
CHEM 212 Module 4 - Original Practice Exam Page 2
, Rationale: Many monosaccharides fit the approximate empirical formula (CH2O)n, although important carbohydrate
derivatives may not.
5. A six-carbon monosaccharide is called a:
A. Hexose
B. Pentose
C. Triose
D. Heptose
Correct Answer: A. Hexose
Rationale: The prefix hex- denotes six carbons.
6. A five-carbon monosaccharide is called a:
A. Octose
B. Hexose
C. Pentose
D. Tetrose
Correct Answer: C. Pentose
Rationale: The prefix pent- denotes five carbons.
7. Which pair consists entirely of hexoses?
A. Ribose and deoxyribose
B. Glyceraldehyde and fructose
C. Glucose and fructose
D. Ribose and glucose
Correct Answer: C. Glucose and fructose
Rationale: Glucose and fructose each contain six carbon atoms.
8. Which monosaccharide is an aldohexose?
A. Glucose
B. Fructose
C. Ribulose
D. Dihydroxyacetone
Correct Answer: A. Glucose
Rationale: Glucose contains six carbons and an aldehyde-derived carbonyl in its open-chain form.
9. Which monosaccharide is a ketohexose?
A. Ribose
CHEM 212 Module 4 - Original Practice Exam Page 3
