Which of the following occurs in the pancreatic β cell when blood glucose levels increase? A) Insulin is secreted by receptor-mediated endocytosis. B) Intracellular ATP/ADP levels increase. C) K⁺ channels open, altering the membrane potential. D) Ca²⁺ channels close. E) All of the above occur.

Question

Quizplus · Accepted Answer

When blood glucose levels increase, glucose enters the pancreatic β cells through glucose transporters, leading to an increase in intracellular ATP production from glucose metabolism. This rise in ATP/ADP ratio leads to the closure of ATP-sensitive potassium channels, causing cell depolarization, which in turn opens voltage-dependent calcium channels. The influx of calcium ions triggers the exocytosis of insulin-containing vesicles. Therefore, the correct response is that intracellular ATP/ADP levels increase.

Which of the Following Occurs in the Pancreatic β Cell