Primary structure
The A chain of insulin is 21 amino acids long and the B chain is 30 amino acids long, and each sequence is unique to the insulin protein.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"OpenStax College, Proteins. October 16, 2013."
http://cnx.org/content/m44402/latest/Figure_03_04_04.jpg
OpenStax CNX
CC BY 3.0.
