2.3 Hormonal Control of Cellular Metabolism

Question 1

How does glucose regulate insulin secretion in pancreatic beta cells?

Answer 1

When blood glucose levels are high, active metabolism of glucose in the beta cell raises intracellular [ATP], closing K channels in teh plasma membrane and depolarising it. In response to the change voltage gated Ca channels open allowing Ca to flow into the cell. Ca is now high enough to trigger insulin release by exocytosis

Question 2

what is the stimulus for insulin release?

Answer 2

rise in plasma glucose

Question 3

what is the stimulus for glucagon release?

Answer 3

low blood sugar (decrease ATP/ADP), elevated bloos amino acids

Question 4

what is the stimulus for adrenaline release?

Answer 4

major stressors