Which of the following statements is not correct ?
Option: 1 In man insulin is synthesised as a proinsulin
Option: 2 The proinsulin has an extra peptide called C-peptide
Option: 3 The functional insulin has A and B chains linked together by hydrogen bonds
Option: 4 Genetically engineered insulin is produced in E-coli.
The functional insulin has A and B chain bonded by the disulfide bridge. Hence, the correct option is (c).