How is insulin secretion controlled?

Beta cells in the pancreas contain potassium and calcium ion channels - potassium ion channels are normally open and calcium channels closed. When glucose concentrations outside of the cell are high the glucose molecules will diffuse down the concentration gradient and into the cell. The glucose now inside the cell is quickly metabolised into ATP. An increase in the concentration of ATP inside the cell causes the potassium ion channels to close - as the positive ions are not able to leave the cell, the cell becomes less negative inside. This change in the potential across the membrane causes voltage gated calcium ion channels to open and calcium ions diffuse into the cell. Presence of calcium causes movement of vesicles containing insulin to move towards the cell membrane where they fuse and are released by exocytosis.

Answered by Bethany F. Biology tutor

7946 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Why are nitrogen and phosphorus vital in photosynthesising plants


Why is glycogen suitable for energy storage in cells?


why does vision using the fovea have high visual acuity, but low sensitivity to light compared with vision using other parts of the retina.


During the cardiac cycle , there is a delay between the excitation of the atria and excitation of the ventricles. Explain how this is achieved and why this delay is essential.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences