What is the pathway of the synthesis and secretion of insulin?

Insulin synthesis begins in the pancreas's beta cells, where preproinsulin is synthesized in the rough endoplasmic reticulum (RER). It is then processed into proinsulin, which is transported to the Golgi apparatus, where it matures into insulin through the removal of the C-peptide. The mature insulin is stored in secretory granules until glucose levels rise, triggering exocytosis, which releases insulin into the bloodstream. This process helps regulate blood sugar levels effectively.