insulin secretion Flashcards
where is insulin secreted from?
beta cells of islets of langerhans in the pancreas
what do alpha cells produce
glucagon
What initial step triggers insulin secretion
Blood glucose concentration is high, so more glucose enters a beta cells by facilitated diffusion
what happens when glucose enters the cell
More glucose in beta cells, causes the respiration to increase making more ATP
what did an increase in ATP cause
atp sensitive potassium(K+)channels close
what does the closure of k+ channels cause?
This means potassium ions can’t get through the membranes they build up inside the cell, Causing The plasma membrane to depolarise
depolarisation definition
The inside of the beta cell is less negative because there are more positively charged potassium ions inside the cell
what does depolarisation lead to
ca+ion channels open
what does the opening of the ca+ channel ions result in
influx of ca+ ions inside the cell
what doe a ca+ influx cause
signals insulin filled vesicle to merge with membrane(exocytosis) secretion of insulin
