Explanation:

Insulin is a hormone that is important for metabolism and utilization of energy from the ingested nutrients - especially glucose.

Insulin chemistry and etymology
Insulin is a protein chain or peptide hormone. There are 51 amino acids in an insulin molecule. It has a molecular weight of 5808 Da.

Insulin is produced in the islets of Langerhans in the pancreas. The name insulin comes from the Latin ''insula'' for "island" from the cells that produce the hormone in the pancreas.

Insulin's structure varies slightly between species of animal. Both porcine (from pigs) and bovine (from cows) insulin are similar to human insulin but porcine insulin resembles human insulin more closely.