C- peptide is secreted by ?

Ans. is 'b' i.e., B cellsInsulin is a polypeptide hormone which is synthesized as a larger preprohormone (preproinsulin).Asthepreprohormone enters the endoplasmic reticulum, 23 amino-acid signal peptide is removed and it is conveed to prohormone (proinsulin).Proinsulin is made up A and B chain connected by a connecting peptide (C-peptide or C-chain).C-peptide is detached in the granules before secretion. Normally, 90-97% of the product released from B cells is insulin along with equimolar amounts of C-peptide.Insulin is a two chain polypeptide having 51 aminoacids : The A chain has 21 while B-chain has 30-aminoacids.Half life of insulin is about 5 minutes.