MCT NBME Review Questions and Answers

MCT NBME Review Questions and Answers B - Ans:-(Marks' Medical Biochemistry Chapter 5) A patient was diagnosed with one of the types of sphingolipidoses, which are congenital diseases involving the ability to degrade sphingolipids. All sphingolipids have in common which one of the following? A. a glycerol backbone B. ceramide C. phosphorylcholine D. N-acetylneuraminic acid (NANA) B - Ans:-(Marks' Medical Biochemistry Chapter 6) Protein kinases phosphorylate proteins only at certain hydroxyl groups on amino acid side chains. Which of the following groups of amino acids all contain side-chain hydroxyl groups? A. aspartate, glutamate, serine B. serine, threonine, tyrosine ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 2/103 C. lysine, arginine, proline D. alanine, asparagine, serine A - Ans:-(Marks' Medical Biochemistry Chapter 13, #5) Autopsies of patients with Alzheimer disease show protein aggregates called neurofibrillary tangles and neuritic plaques in various regions of the brain. These plaques exhibit the characteristic staining of amyloid. Which of the following structural features is the most likely characteristic of at least one protein in these plaques? A. a high content of beta-pleated sheet structure B. a high content of alpha-helical structure C. a high content of random coils D. disulfide bond cross-links between polypeptide chains B - Ans:-(Marks' Medical Biochemistry Chapter 13, #5) The key mechanistic failure in patients with xeroderma pigmentosum involves which of the following? A. Mutation in the primase gene B. Inability to excise a section of the UV-damaged DNA ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 3/103 C. Mutation of one of the mismatch repair components D. Inability to synthesize DNA across the damaged region E. Loss of proofreading capacity C - Ans:-(Marks' Medical Biochemistry Chapter 30, #3) A newborn is diagnosed with neonatal jaundice. In this patient, the bilirubin produced lacks which of the following carbohydrates? A. glucose B. fructose C. glucuronate D. galactose E. galactitol D - Ans:-(Marks' Medical Biochemistry Chapter 31, #1) A common intermediate in the conversion of glycerol and lactate to glucose is which of the following? A. pyruvate B. oxaloacetate ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 4/103 C. malate D. glucose-6-phosphate E. phosphoenolpyruvate A - Ans:-(Marks' Medical Biochemistry Chapter 31, #2) A patient presented with a bacterial infection that produced an endotoxin that inhibits phosphoenolpyruvate carboxykinase (PEPCK). In this patient, then, under these conditions, glucose production from which of the following precursors would be inhibited? A. alanine B. glycerol C. even-chain fatty acids D. phosphoenolpyruvate E. galactose C - Ans:-(Marks' Medical Biochemistry Chapter 31, #3) Which of the following statements best describes glucagon? A. It acts as an anabolic hormone. ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 5/103 B. It acts on skeletal muscle, liver, and adipose tissue. C. It acts primarily on the liver and adipose tissue. D. Its concentration in the blood increases after a high-carbohydrate meal. E. Its concentration increases in the blood when insulin levels increase. A - Ans:-(Marks' Medical Biochemistry Chapter 48, #4) A patient presented with dysmorphia and cerebellar degeneration. Analysis of his blood indicated elevated levels of phytanic acid and very long chain fatty acids, but no