Describe the events that modulate the release of insulin in beta cells. (4)

This is a describe question - it should be answered directly with only the appropriate factual information.
Glucose enters the beta cells via specific glucose transporters embedded in the cell membrane (GLUT2). The glucose that enters is subsequently phosphorylated to glucose-6-phosphate (G6P) by glucokinase enzymes. G6P enters the glycolytic pathway, and then into the Krebs cycle, where ATP molecules are produced. This causes a rise in the intracellular ATP:ADP ratio. This increased ratio closes the ATP-sensitive potassium channels, preventing potassium ions from leaving the cell. The build up of K+ ions leads to the depolarisation of the cell surface membrane. This depolarisation causes voltage-gated calcium channels to open, permitting the influx of calcium ions into the cell. The increase in intracellular Ca2+ ions results in the movement of insulin-containing vesicles to the membrane, where the insulin is then exocytosed.