IPA: //proʊˈɪn.su.lɪn//
KK: /proʊˈɪn.su.lɪn/
A type of protein that is the initial form of insulin in the body, which is changed into insulin through a chemical process.
Proinsulin is produced in the pancreas and is essential for the regulation of blood sugar levels.
Proinsulin is formed from "pro-" (meaning before) and "insulin" (from Latin "insula", meaning island, referring to the islets of Langerhans in the pancreas where insulin is produced). The term proinsulin refers to the precursor form of insulin, which is produced before it is converted into active insulin.
Think of 'pro-' meaning 'before' and 'insulin' referring to the hormone produced in the pancreas. This helps you remember that proinsulin is the form that comes before insulin.