BCH 4024 OC 3426 SP26 E2 Q14: A patient on high‑dose theophylline (a phosphodiesterase inhibitor) arrives with tremor and tachycardia. At the cellular level, which immediate change in β‑adrenergic signaling best fits?

BCH 4024 OC 3426 SP26 E2 Q24: What is the hormonal signal that reduces F2,6BP levels in hepatocytes, thereby favoring gluconeogenesis?

BCH 4024 OC 3426 SP26 E2 Q1: A muscle biopsy from a patient with unexplained weakness shows abundant synaptic vesicles accumulated near the neuromuscular junction, with little neurotransmitter release. The responsible mutation prevents vesicle proteins from forming a stable complex with membrane proteins. Which protein family is most directly impaired?

BCH 4024 OC 3426 SP26 E2 Q4: Malate‑aspartate shuttle activity increases during fasting in the liver. Which statement best explains why?

The next 3 questions (10-12) are based on the following clinical case: A 32-year-old male with Type 2 diabetes is being treated with a drug that enhances insulin signaling and glucose uptake. He also takes a medication that acts as an antagonist and targets β-adrenergic receptors to manage hypertension (high blood pressure). After a few weeks, he reports improved glucose control but experiences episodes of dizziness and fatigue. BCH 4024 OC 3426 SP26 E2 Q10: Which signaling pathway is primarily enhanced by the insulin-sensitizing drug?

BCH 4024 OC 3426 SP26 E2 Q8: A neuron is stimulated by a neurotransmitter that opens ligand‑gated Cl⁻ channels on the postsynaptic membrane. What effect will this have on membrane potential?

BCH 4024 OC 3426 SP26 E2 Q7: A small-molecule inhibitor blocks the interaction between Grb2 and Sos without affecting Grb2’s ability to bind the RTK. Which outcome is expected?

BCH 4024 OC 3426 SP26 E2 Q16: You see in your clinic a patient who complains that they are unable to carry out long, intensive exercise. You have a muscle biopsy performed, and the results indicate a deficiency in the enzyme that catalyzes the following reaction. What is the enzyme, and why does a deficiency of this enzyme lead to rapid muscle fatigue?

BCH 4024 OC 3426 SP26 E2 Q23: Which glycolytic intermediate is directly shared with the pentose phosphate pathway and determines whether glucose flux enters glycolysis or the PPP?

BCH 4024 OC 3426 SP26 E2 Q17: A newly discovered four‑pass membrane protein shows one 22‑residue hydrophobic segment near residue 40 and three similar hydrophobic segments later in the sequence. Lys/Arg clusters are enriched on the loop/intervening sequence between helix 2 and helix 3. Given these observations, which overall orientation is most consistent with membrane topology rules?