I/GCSE Biology Question Analysis Topic: Biology - Insulin
Mention the chemical change that proinsulin undergoes, to be able to act as mature insulin.
Insulin's precursor, proinsulin, is kept in the pancreatic beta islet cells of Langerhans. The C-peptide connects the insulin B and A subunits to form the single polypeptide chain known as proinsulin.
Proinsulin undergoes a chemical transformation that involves the cleavage of the C peptide with the help of type I and type II endoproteases. While proinsulin travels through the Golgi apparatus to be cleaved, this transformation occurs in the Langerhans islet cells.
End of analysis. Great!