UNE MEDICAL BIOCHEMISTRY EXAM QUESTIONS AND ANSWERS 2025

A comatose infant is brought to the ER. In the course of the examination, plasma ammonia was found to be elevated 20-fold over normal values. Urine orotic acid and uracil were both greater than normal. A defect of which of the following enzymes is the most likely diagnosis? - Ornithine transcarbamoylase Your patient presents with a deficiency of the enzyme that catalyzes synthesis of N-acetylglutamate (NAGs). Which of the following would be a consequence of this deficiency in the patient? - Increased amino acids in the blood The cellular uptake of LDL increases intracellular cholesterol levels. This has which of the following impacts on de novo cholesterol synthesis? - Increases degradation of HMG-CoA reductase Dietary cholesterol is primarily transported in the body by which of the following lipoproteins? - Chylomicron Secondary bile salts are generated by bacterial modification of primary bile salts in the intestinal lumen. These modifications have which of the following impacts on bile salt solubility? - Decrease solubility A 47-year-old male is prescribed a statin (HMG-CoA reductase inhibitor) to manage his elevated LDL cholesterol. What is the initial mechanism of action for obtaining the desired effect in this man? - Decreasing hepatic cholesterol biosynthesis