ESTUDYR
WGU C785 MODULE 5| MULTICHOICE ANSWERED EXAM
QUESTIONS WITH DETAILED RATIONALES
1. Which characteristic best explains why phospholipids spontaneously form bilayers in
aqueous environments?
A. Their glycerol backbone resists hydrogen bonding
B. Their nonpolar tails form ionic interactions
C. Their amphipathic nature drives hydrophobic interactions
D. Their phosphate groups attract hydrocarbons
⭐Correct Answer: C – Their amphipathic nature drives hydrophobic interactions⭐
Rationale: Phospholipids contain hydrophobic fatty acid tails and hydrophilic phosphate heads.
Water excludes the nonpolar tails, causing bilayer formation—this is the foundation of
membrane structure.
2. Beta oxidation produces which direct product that enters the citric acid cycle?
A. NADH only
B. Acetyl-CoA
C. FAD
D. Citrate
⭐Correct Answer: B – Acetyl-CoA⭐
Rationale: Fatty acids undergo sequential two-carbon cleavage, generating acetyl-CoA units
that feed directly into the citric acid cycle for ATP production.
3. Which molecule is essential for emulsifying dietary lipids in the small intestine?
A. Chylomicrons
B. Bile salts
C. Acetyl-CoA
D. Lipoprotein lipase
⭐Correct Answer: B – Bile salts⭐
Rationale: Bile salts are amphipathic derivatives of cholesterol that emulsify lipids, increasing
surface area for pancreatic lipase activity.
,ESTUDYR
4. Chylomicrons are primarily responsible for transporting which type of molecule?
A. Intracellular glucose
B. Dietary triglycerides
C. Liver-derived cholesterol
D. Ketone bodies
⭐Correct Answer: B – Dietary triglycerides⭐
Rationale: Chylomicrons deliver dietary triglycerides from the intestines to tissues via lymphatic
circulation.
5. Cis-double bonds in fatty acids are important because they…
A. Allow tighter packing of lipid chains
B. Increase melting point
C. Introduce kinks that prevent solidification
D. Convert fatty acids into ketone bodies
⭐Correct Answer: C – Introduce kinks that prevent solidification⭐
Rationale: Cis-double bonds bend the hydrocarbon chain, reducing intermolecular forces and
lowering the melting point.
6. What pathophysiological event causes diabetic ketoacidosis (DKA)?
A. Excess insulin uptake
B. Increased glucose oxidation
C. Excessive ketone body accumulation lowering blood pH
D. Pancreatic inhibition of lipid breakdown
⭐Correct Answer: C – Excessive ketone body accumulation lowering blood pH⭐
Rationale: Ketogenesis accelerates in insulin deficiency, producing acidic ketone bodies that
lower systemic pH.
7. Essential fatty acids are defined as those…
, ESTUDYR
A. Synthesized from acetyl-CoA
B. With saturated carbon chains
C. That humans cannot synthesize
D. Found only in animal tissue
⭐Correct Answer: C – That humans cannot synthesize⭐
Rationale: Humans lack enzymes to introduce double bonds near the methyl (omega) end; thus
omega-3 and omega-6 fatty acids must be consumed.
8. Glycolipids differ from phospholipids because they contain…
A. A phosphate head group
B. A carbohydrate attached by a glycosidic bond
C. Three fatty acids
D. No hydrophobic region
⭐Correct Answer: B – A carbohydrate attached by a glycosidic bond⭐
Rationale: Glycolipids incorporate sugars into their structure, important for cell recognition.
9. Hydrophobic molecules are best described as…
A. Readily soluble in water
B. Ionizable in acidic solutions
C. Dominated by C-H and C-C bonds
D. Strongly attracted to polar molecules
⭐Correct Answer: C – Dominated by C-H and C-C bonds⭐
Rationale: Nonpolar molecules exhibit hydrophobic interactions due to lack of charge and
inability to hydrogen-bond.
10. Ketogenesis occurs primarily in which organ?
A. Kidneys
B. Liver
C. Muscle
D. Pancreas
WGU C785 MODULE 5| MULTICHOICE ANSWERED EXAM
QUESTIONS WITH DETAILED RATIONALES
1. Which characteristic best explains why phospholipids spontaneously form bilayers in
aqueous environments?
A. Their glycerol backbone resists hydrogen bonding
B. Their nonpolar tails form ionic interactions
C. Their amphipathic nature drives hydrophobic interactions
D. Their phosphate groups attract hydrocarbons
⭐Correct Answer: C – Their amphipathic nature drives hydrophobic interactions⭐
Rationale: Phospholipids contain hydrophobic fatty acid tails and hydrophilic phosphate heads.
Water excludes the nonpolar tails, causing bilayer formation—this is the foundation of
membrane structure.
2. Beta oxidation produces which direct product that enters the citric acid cycle?
A. NADH only
B. Acetyl-CoA
C. FAD
D. Citrate
⭐Correct Answer: B – Acetyl-CoA⭐
Rationale: Fatty acids undergo sequential two-carbon cleavage, generating acetyl-CoA units
that feed directly into the citric acid cycle for ATP production.
3. Which molecule is essential for emulsifying dietary lipids in the small intestine?
A. Chylomicrons
B. Bile salts
C. Acetyl-CoA
D. Lipoprotein lipase
⭐Correct Answer: B – Bile salts⭐
Rationale: Bile salts are amphipathic derivatives of cholesterol that emulsify lipids, increasing
surface area for pancreatic lipase activity.
,ESTUDYR
4. Chylomicrons are primarily responsible for transporting which type of molecule?
A. Intracellular glucose
B. Dietary triglycerides
C. Liver-derived cholesterol
D. Ketone bodies
⭐Correct Answer: B – Dietary triglycerides⭐
Rationale: Chylomicrons deliver dietary triglycerides from the intestines to tissues via lymphatic
circulation.
5. Cis-double bonds in fatty acids are important because they…
A. Allow tighter packing of lipid chains
B. Increase melting point
C. Introduce kinks that prevent solidification
D. Convert fatty acids into ketone bodies
⭐Correct Answer: C – Introduce kinks that prevent solidification⭐
Rationale: Cis-double bonds bend the hydrocarbon chain, reducing intermolecular forces and
lowering the melting point.
6. What pathophysiological event causes diabetic ketoacidosis (DKA)?
A. Excess insulin uptake
B. Increased glucose oxidation
C. Excessive ketone body accumulation lowering blood pH
D. Pancreatic inhibition of lipid breakdown
⭐Correct Answer: C – Excessive ketone body accumulation lowering blood pH⭐
Rationale: Ketogenesis accelerates in insulin deficiency, producing acidic ketone bodies that
lower systemic pH.
7. Essential fatty acids are defined as those…
, ESTUDYR
A. Synthesized from acetyl-CoA
B. With saturated carbon chains
C. That humans cannot synthesize
D. Found only in animal tissue
⭐Correct Answer: C – That humans cannot synthesize⭐
Rationale: Humans lack enzymes to introduce double bonds near the methyl (omega) end; thus
omega-3 and omega-6 fatty acids must be consumed.
8. Glycolipids differ from phospholipids because they contain…
A. A phosphate head group
B. A carbohydrate attached by a glycosidic bond
C. Three fatty acids
D. No hydrophobic region
⭐Correct Answer: B – A carbohydrate attached by a glycosidic bond⭐
Rationale: Glycolipids incorporate sugars into their structure, important for cell recognition.
9. Hydrophobic molecules are best described as…
A. Readily soluble in water
B. Ionizable in acidic solutions
C. Dominated by C-H and C-C bonds
D. Strongly attracted to polar molecules
⭐Correct Answer: C – Dominated by C-H and C-C bonds⭐
Rationale: Nonpolar molecules exhibit hydrophobic interactions due to lack of charge and
inability to hydrogen-bond.
10. Ketogenesis occurs primarily in which organ?
A. Kidneys
B. Liver
C. Muscle
D. Pancreas
