Which of the following statements is false?
I. | Insulin was originally extracted from pancreas of slaughtered pigs and cattle |
II. | Animal insulin is difficult to obtain |
III. | Animal insulin is identical to human insulin |
IV. | Non-human insulin caused some patients to develop allergy |
V. | Recombinant DNA allowed scientists to insert a human insulin gene into a bacterial expression vector |
VI. | Recombinant insulin is actually obtained from E. coli bacterial cell |
1. Only I and II
2. Only III and IV
3. Only III
4. Only VI
Which step proved to be the main challenging obstacle in the production of human insulin by genetic engineering?
1. | Splitting A and B polypeptide chains |
2. | Addition of C-peptide to pro-insulin |
3. | Getting insulin assembled into mature form |
4. | Removal of C-peptide from active insulin |