Describe and explain the process of insulin secretion

Beta cells store insulin in vesiclesAt normal blood glucose concentration (BGC), K+ channels are open, so K+ can diffuse out of the cell to maintain the potential difference (PD) at -70mVWhen the BGC rises, glucose enters the cells by facilitated diffusion via transporter proteinsThis glucose is phosphorylated in the cell by glucokinase and is used in metabolism to produce ATPK+ channels are ATP sensitive so they close, meaning the PD reduces to -30mV as K+ can no longer diffuse out (more positive ions in the cell)This depolarisation causes voltage-gated Ca2+ channels to openCa2+ diffuses into the cell, triggering the fusion of the vesicles with the cell membraneThe insulin is then secreted out of the cell via exocytosis

SH
Answered by Summia H. Biology tutor

2352 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

What is the difference between aerobic and anaerobic respiration?


Outline the folding of a protein to form its 3D structure.


Explain the consequences of using high levels of nitrogenous fertilisers


Using the Hardy Weinberg principle, calculate the frequency of the heterozygous genotype in the population if the frequency of the dominant allele p is 0.864. Express your answer as a percentage of the population.


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