Question: which one of the following enzymes is involved in both glycogenesis and glycogenolysis?
Answer: Phosphofructokinase-1 is the rate-limiting enzyme for glycolysis, while fructose 1,6-bisphosphatase is the rate-limiting enzyme for gluconeogenesis. The metabolism of glucose is mainly controlled by hormones such as insulin, which stimulates glycolysis, and glucagon, which stimulates gluconeogenesis.