In the insulin sequence, what is the third event after the second event?

• A. Glucose enters the bloodstream
• B. Insulin transports glucose to muscle cells
• C. Glycogen stored in the liver
• D. Glycogen converted to glucose by alpha cells

Answer: (B)

The key idea is how insulin lowers blood glucose by promoting glucose uptake into tissues after its release. Once glucose rises and insulin is released, the next step is insulin signaling causing skeletal muscle to take up glucose. Insulin triggers GLUT4 transporters to move to the muscle cell membrane, allowing glucose to enter the cells for use or storage. This uptake is the third event after insulin release and sets the stage for glycogen synthesis in muscle and liver. The notion of glycogen storage in the liver would follow uptake, and the idea of alpha cells converting glycogen to glucose describes glucagon’s action, which raises blood glucose rather than promoting uptake.