Development of insulin: translation of the mRNA in pre-pro-insulin in the ribosome.
Pre-pro-insulin is made of: pre-sequence (signal sequence, 24 amino acids, here blue), b-chain (30 amino acids, yellow), c-peptide (31 amino acids +2, red), and a-chain (21 amino acids, yellow), 107 amino acids in total.
Subsequently the pre-pro-insulin is folded forming 3 di-sulfide bridges. The molecule leaves the endoplasmic reticulum splitting off the signaling sequence and pro-insulin (84 amino acids) develops. It is saved in the Golgi apparatus. When necessary, the pro-peptide is cut off and final insulin is released.