Questions 24 through 26 are based on the following clinical case: A 16-year-old athlete collapses during a high-intensity training session. He is found to be hypoglycemic (low blood glucose), with elevated lactate and low insulin levels. Blood tests show elevated epinephrine and glucagon. A muscle biopsy reveals normal glycogen stores but impaired mobilization of glucose from glycogen. Liver biopsy shows increased gluconeogenic activity and reduced glycogen synthesis. BCH4024 OC F25 E2 Q25: Which of the following best explains the impaired glucose utilization from muscle despite normal glycogen stores?

BCH4024 OC F25 E2 Q50: A mutation prevents autophosphorylation of the insulin receptor. What is the most likely consequence?

BCH4024 OC F25 E2 Q29: In individuals with porphyria, the inability to produce sufficient porphyrins (see structure) primarily affects which part of metabolism?

BCH4024 OC F25 E2 Q16: A mutation prevents autophosphorylation of the insulin receptor. Which downstream effect is most likely impaired?

Questions 20 & 21 are based on the following case scenario: A 3-year-old child with a known glucose-6-phosphate dehydrogenase (G6PD) deficiency is treated with antimalarial drugs. Shortly after, she develop jaundice and fatigue. BCH4024 OC F25 E2 Q20: What is the most likely cause?

BCH4024 OC F25 E2 Q40: A defect in α-ketoglutarate dehydrogenase would most directly impair which of the following processes?

BCH4024 OC F25 E2 Q11: Which second messenger is produced by phospholipase C activation?

BCH4024 OC F25 E2 Q30: A 1 year-old male has poor feeding, lethargy, and seizures. Lab tests show elevated levels of α-ketoglutarate and decreased levels of succinyl-CoA. You suspect a problem with the citric acid cycle and think he MOST likely has a deficiency of:

BCH4024 OC F25 E2 Q35: One enzyme of the glycolytic pathway is regulated by feed forward activation. Which of the following pairs listed below gives the correct enzyme and the regulatory intermediate? Enzyme Intermediate A phosphofructokinase glucose 6-phosphate B hexokinase 2-phosphoglycerate C pyruvate kinase fructose 1,6-bisphosphate D phosphoglycerate kinase fructose 2,6-bisphosphate E glyceraldehyde 3-phosphate dehydrogenase fructose 6-phosphate

Questions 9 & 10 are based on the following case: A 24-year-old patient presents with asthma-like symptoms. She is administered a β₂-adrenergic agonist. Her symptoms improve rapidly. BCH4024 OC F25 E2 Q10: Which downstream effect is most likely contributing to the improvement observed?