Biochem 210 Module 5 Exam - Portage Learning Latest Update 2026
Domain 1: Fatty Acids & Triacylglycerols (Q1–40)
Q1. Which of the following is a polyunsaturated fatty acid (PUFA)?
A) A fatty acid with only single bonds
B) A fatty acid containing two or more double bonds
C) A fatty acid with one double bond
D) A saturated fatty acid
Answer: B
Rationale: Polyunsaturated fatty acids (PUFAs) contain two or more double
bonds. The term "poly" means many, indicating multiple points of unsaturation .
Q2. A particular lipid is a liquid at room temperature. It is called a(n):
A) Fat
B) Oil
,C) Wax
D) Steroid
Answer: B
Rationale: Oils are lipids that remain liquid at room temperature due to a higher
proportion of unsaturated fatty acids, which introduce kinks preventing tight
packing .
Q3. What is the effect of a double bond on the structure of a fatty acid?
A) It straightens the hydrocarbon chain
B) It causes the fatty acid to bend or kink
C) It increases the melting point
D) It prevents any interaction with other molecules
Answer: B
Rationale: A cis double bond introduces a rigid bend (kink) in the hydrocarbon
chain, preventing tight packing and increasing fluidity .
Q4. Which notation represents a fatty acid with two double bonds?
A) 18:1(Δ9)
,B) 18:2(Δ9,12)
C) 18:0
D) 20:4(Δ5,8,11,14)
Answer: B
Rationale: The notation 18:2 indicates 18 carbons and 2 double bonds—the
number after the colon denotes the number of double bonds .
Q5. Which simplified notation indicates a 20-carbon omega-3 fatty acid that
contains no other double bonds?
A) 20:1 (Δ11)
B) 20:1 (Δ18)
C) 20:1 (Δ17)
D) 20:1 (Δ3)
Answer: C
Rationale: An omega-3 fatty acid has its first double bond at carbon 3 from the
methyl (omega) end. With 20 carbons, the first double bond must be between
carbons 17 and 18, thus Δ17 .
, Q6. A fatty acid with only single bonds is described as:
A) Unsaturated
B) Saturated
C) Polyunsaturated
D) Monounsaturated
Answer: B
Rationale: Saturated fatty acids have no double bonds—the carbon chain is fully
"saturated" with hydrogen atoms .
Q7. Triacylglycerols are made from:
A) A glycerol backbone only
B) Three fatty acids only
C) A glycerol backbone and three fatty acids
D) A sphingosine backbone
Answer: C
Rationale: Triacylglycerols (triglycerides) consist of one glycerol molecule
esterified to three fatty acids via ester linkages .
Domain 1: Fatty Acids & Triacylglycerols (Q1–40)
Q1. Which of the following is a polyunsaturated fatty acid (PUFA)?
A) A fatty acid with only single bonds
B) A fatty acid containing two or more double bonds
C) A fatty acid with one double bond
D) A saturated fatty acid
Answer: B
Rationale: Polyunsaturated fatty acids (PUFAs) contain two or more double
bonds. The term "poly" means many, indicating multiple points of unsaturation .
Q2. A particular lipid is a liquid at room temperature. It is called a(n):
A) Fat
B) Oil
,C) Wax
D) Steroid
Answer: B
Rationale: Oils are lipids that remain liquid at room temperature due to a higher
proportion of unsaturated fatty acids, which introduce kinks preventing tight
packing .
Q3. What is the effect of a double bond on the structure of a fatty acid?
A) It straightens the hydrocarbon chain
B) It causes the fatty acid to bend or kink
C) It increases the melting point
D) It prevents any interaction with other molecules
Answer: B
Rationale: A cis double bond introduces a rigid bend (kink) in the hydrocarbon
chain, preventing tight packing and increasing fluidity .
Q4. Which notation represents a fatty acid with two double bonds?
A) 18:1(Δ9)
,B) 18:2(Δ9,12)
C) 18:0
D) 20:4(Δ5,8,11,14)
Answer: B
Rationale: The notation 18:2 indicates 18 carbons and 2 double bonds—the
number after the colon denotes the number of double bonds .
Q5. Which simplified notation indicates a 20-carbon omega-3 fatty acid that
contains no other double bonds?
A) 20:1 (Δ11)
B) 20:1 (Δ18)
C) 20:1 (Δ17)
D) 20:1 (Δ3)
Answer: C
Rationale: An omega-3 fatty acid has its first double bond at carbon 3 from the
methyl (omega) end. With 20 carbons, the first double bond must be between
carbons 17 and 18, thus Δ17 .
, Q6. A fatty acid with only single bonds is described as:
A) Unsaturated
B) Saturated
C) Polyunsaturated
D) Monounsaturated
Answer: B
Rationale: Saturated fatty acids have no double bonds—the carbon chain is fully
"saturated" with hydrogen atoms .
Q7. Triacylglycerols are made from:
A) A glycerol backbone only
B) Three fatty acids only
C) A glycerol backbone and three fatty acids
D) A sphingosine backbone
Answer: C
Rationale: Triacylglycerols (triglycerides) consist of one glycerol molecule
esterified to three fatty acids via ester linkages .
