Portage Biochemistry- Module 4 questions
and answers 2025\2026 A+ Grade
Is the following molecule an aldose or ketose? Briefly explain.
- correct answer ketose. There is a C=O on the third carbon from the top.
Which carbon in erythrose would tell you if the monosaccharide is D or L? Give the carbon's number in
your answer.
- correct answer On carbon number 3, which is the penultimate carbon.
Glucose and mannose are epimers. Name another epimer of glucose besides mannose.
- correct answer Galactose
Is the following structure a D or L carbohydrate? Briefly explain.
- correct answer L. The -OH group is on the left side on the penultimate carbon.
Does the compound C7H14O8 fit the formal definition of a carbohydrate? Explain.
- correct answer No. This compound has does not fit the formula CnH2nOn as indicated in the module.
There is one additional oxygen in this compound.
Which of the following is carbon number 3? (Indicate by the appropriate letter.)
- correct answer C
Which carbon in this molecule is the anomeric carbon? (Indicate by the appropriate letter.)
- correct answer A
Is the following a furan or pyran ring? Briefly explain.
- correct answer furan. There are only five atoms in the ring: one oxygen and four carbons.
, When is the alpha 1→6 connection typically found in carbohydrates?
- correct answer The alpha 1→6 bond is found in polysaccharides when branching occurs.
Is the following an alpha 1→4 or beta 1→4 connection? Briefly explain.
- correct answer This is a beta 1→4 because the molecule on the left has the oxygen in the up, or beta,
position.
What are the similarities and differences between amylose and amylopectin? Explain in at least three
complete sentences.
- correct answer Similarities: Both of are homopolysaccharides of glucose. They each have alpha 1 → 4
connections between glucose. They each are part of starch.
Differences: Amylopectin has branching with alpha 1→6 linkages. Amylose does not. Amylopectin is
typically larger than amylose.
How is chitin different from cellulose?
- correct answer Chitin has glucose with derivatives attached. -NH-CO-CH3 is connected to each glucose.
Where are alpha 1 → 6 bonds found in carbohydrates?
- correct answer They are found where glycogen and amylopectin branch.
In what ways are amylose and a protein alike?
- correct answer They both can form alpha helices.
What is the name of the carbohydrate found in beetle exoskeleton?
- correct answer Chitin
Which of the following monosaccharides is a ketose?
Dihydroxyacetone
Galactose
Glucose
Glyceraldehyde
Idose
- correct answer Dihydroxyacetone
and answers 2025\2026 A+ Grade
Is the following molecule an aldose or ketose? Briefly explain.
- correct answer ketose. There is a C=O on the third carbon from the top.
Which carbon in erythrose would tell you if the monosaccharide is D or L? Give the carbon's number in
your answer.
- correct answer On carbon number 3, which is the penultimate carbon.
Glucose and mannose are epimers. Name another epimer of glucose besides mannose.
- correct answer Galactose
Is the following structure a D or L carbohydrate? Briefly explain.
- correct answer L. The -OH group is on the left side on the penultimate carbon.
Does the compound C7H14O8 fit the formal definition of a carbohydrate? Explain.
- correct answer No. This compound has does not fit the formula CnH2nOn as indicated in the module.
There is one additional oxygen in this compound.
Which of the following is carbon number 3? (Indicate by the appropriate letter.)
- correct answer C
Which carbon in this molecule is the anomeric carbon? (Indicate by the appropriate letter.)
- correct answer A
Is the following a furan or pyran ring? Briefly explain.
- correct answer furan. There are only five atoms in the ring: one oxygen and four carbons.
, When is the alpha 1→6 connection typically found in carbohydrates?
- correct answer The alpha 1→6 bond is found in polysaccharides when branching occurs.
Is the following an alpha 1→4 or beta 1→4 connection? Briefly explain.
- correct answer This is a beta 1→4 because the molecule on the left has the oxygen in the up, or beta,
position.
What are the similarities and differences between amylose and amylopectin? Explain in at least three
complete sentences.
- correct answer Similarities: Both of are homopolysaccharides of glucose. They each have alpha 1 → 4
connections between glucose. They each are part of starch.
Differences: Amylopectin has branching with alpha 1→6 linkages. Amylose does not. Amylopectin is
typically larger than amylose.
How is chitin different from cellulose?
- correct answer Chitin has glucose with derivatives attached. -NH-CO-CH3 is connected to each glucose.
Where are alpha 1 → 6 bonds found in carbohydrates?
- correct answer They are found where glycogen and amylopectin branch.
In what ways are amylose and a protein alike?
- correct answer They both can form alpha helices.
What is the name of the carbohydrate found in beetle exoskeleton?
- correct answer Chitin
Which of the following monosaccharides is a ketose?
Dihydroxyacetone
Galactose
Glucose
Glyceraldehyde
Idose
- correct answer Dihydroxyacetone
