A 55-year-old female with type 2 diabetes mellitus is prescribed metformin, a drug that lowers blood glucose levels by inhibiting gluconeogenesis in the liver. During a routine check-up, she asks how metformin specifically targets gluconeogenesis without affecting glycolysis, given that both pathways share several intermediates. Based on the principles of metabolic compartmentation and regulation, which of the following best explains how metformin selectively inhibits gluconeogenesis?
