Lipid Biochemistry USMLE Step 1 Practice Question
A 28-year-old man presents with recurrent episodes of severe abdominal pain and pancreatitis. His triglyceride level is 1,800 mg/dL. He has earlobe creases and a family history of premature coronary disease. Genetic testing reveals a mutation in the apolipoprotein C-II gene. Which of the following best explains why his triglycerides are markedly elevated?
Answer choices
- AApolipoprotein C-II inhibits hepatic cholesteryl ester transfer protein
- BApolipoprotein C-II competitively inhibits apolipoprotein E binding
- CApolipoprotein C-II promotes VLDL secretion from hepatocytes
- DApolipoprotein C-II is a required cofactor for lipoprotein lipase activityCorrect answer
- EApolipoprotein C-II prevents apolipoprotein B-100 oxidation
- FApolipoprotein C-II enhances the uptake of chylomicrons by hepatic receptors
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.