BIOCHEM 210 MODULE 4 EXAM - PORTAGE LEARNING LATEST UPDATE 2026.
BIOCHEM 210 Module 4 Exam: Question Bank
1. Which of the following is the most common monosaccharide on Earth?
A) Ribose
B) Fructose
C) Sucrose
D) Glucose
E) Chitin
Answer: D) Glucose
Rationale: Glucose is the most abundant monosaccharide because it is the
primary product of photosynthesis and a key energy source for most organisms .
2. According to the formal definition, a carbohydrate is a biomolecule with the
general formula of (CH₂O)ₙ. Which of the following compounds does NOT fit this
definition?
A) C₆H₁₂O₆
B) C₅H₁₀O₅
C) C₇H₁₀O₇
,D) C₄H₈O₄
E) C₃H₆O₃
Answer: C) C₇H₁₀O₇
Rationale: While many carbohydrates fit the (CH₂O)ₙ pattern, this is not absolute.
However, C₇H₁₀O₇ does not fit the simple n: n ratio (it would be C₇H₁₄O₇ if it
followed the pattern), indicating it is likely a derivative .
3. Is the following molecule an aldose or a ketose? (Image of Dihydroxyacetone
described)
A) Aldose
B) Ketose
C) Disaccharide
D) Polysaccharide
E) Anomer
Answer: B) Ketose
Rationale: The molecule is Dihydroxyacetone. The defining feature is the presence
of a ketone group (C=O) on the second carbon of the three-carbon chain, making
it the simplest ketose .
,4. What is the simplest aldose sugar?
A) Dihydroxyacetone
B) Erythrose
C) Glucose
D) Glyceraldehyde
E) Ribose
Answer: D) Glyceraldehyde
Rationale: Glyceraldehyde is a triose (3 carbons) with an aldehyde group at the C1
position. Dihydroxyacetone is a ketose .
5. Fructose is classified as which type of monosaccharide?
A) Aldohexose
B) Ketohexose
C) Aldopentose
D) Ketotetrose
E) Ketoheptose
, Answer: B) Ketohexose
Rationale: Fructose contains 6 carbon atoms (hexose) and features a ketone
functional group (ketose), specifically on carbon number 2 .
6. Which of the following monosaccharides is NOT an aldose?
A) Erythrose
B) Dihydroxyacetone
C) Glucose
D) Glyceraldehyde
E) Ribose
Answer: B) Dihydroxyacetone
Rationale: Dihydroxyacetone is the only common ketotriose among the options.
Erythrose, Glucose, Glyceraldehyde, and Ribose all contain an aldehyde group .
7. Which carbon determines whether a monosaccharide is classified as D or L?
A) The anomeric carbon
B) The carbon with the ketone group
C) The penultimate carbon (chiral carbon farthest from the carbonyl)
D) The terminal methyl carbon
BIOCHEM 210 Module 4 Exam: Question Bank
1. Which of the following is the most common monosaccharide on Earth?
A) Ribose
B) Fructose
C) Sucrose
D) Glucose
E) Chitin
Answer: D) Glucose
Rationale: Glucose is the most abundant monosaccharide because it is the
primary product of photosynthesis and a key energy source for most organisms .
2. According to the formal definition, a carbohydrate is a biomolecule with the
general formula of (CH₂O)ₙ. Which of the following compounds does NOT fit this
definition?
A) C₆H₁₂O₆
B) C₅H₁₀O₅
C) C₇H₁₀O₇
,D) C₄H₈O₄
E) C₃H₆O₃
Answer: C) C₇H₁₀O₇
Rationale: While many carbohydrates fit the (CH₂O)ₙ pattern, this is not absolute.
However, C₇H₁₀O₇ does not fit the simple n: n ratio (it would be C₇H₁₄O₇ if it
followed the pattern), indicating it is likely a derivative .
3. Is the following molecule an aldose or a ketose? (Image of Dihydroxyacetone
described)
A) Aldose
B) Ketose
C) Disaccharide
D) Polysaccharide
E) Anomer
Answer: B) Ketose
Rationale: The molecule is Dihydroxyacetone. The defining feature is the presence
of a ketone group (C=O) on the second carbon of the three-carbon chain, making
it the simplest ketose .
,4. What is the simplest aldose sugar?
A) Dihydroxyacetone
B) Erythrose
C) Glucose
D) Glyceraldehyde
E) Ribose
Answer: D) Glyceraldehyde
Rationale: Glyceraldehyde is a triose (3 carbons) with an aldehyde group at the C1
position. Dihydroxyacetone is a ketose .
5. Fructose is classified as which type of monosaccharide?
A) Aldohexose
B) Ketohexose
C) Aldopentose
D) Ketotetrose
E) Ketoheptose
, Answer: B) Ketohexose
Rationale: Fructose contains 6 carbon atoms (hexose) and features a ketone
functional group (ketose), specifically on carbon number 2 .
6. Which of the following monosaccharides is NOT an aldose?
A) Erythrose
B) Dihydroxyacetone
C) Glucose
D) Glyceraldehyde
E) Ribose
Answer: B) Dihydroxyacetone
Rationale: Dihydroxyacetone is the only common ketotriose among the options.
Erythrose, Glucose, Glyceraldehyde, and Ribose all contain an aldehyde group .
7. Which carbon determines whether a monosaccharide is classified as D or L?
A) The anomeric carbon
B) The carbon with the ketone group
C) The penultimate carbon (chiral carbon farthest from the carbonyl)
D) The terminal methyl carbon
