Question

Which of the following statements is incorrect?
(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.

A) (i) and (ii)
B) (iii) and (iv).
C) Only (iii)
D) Only (vi)

Answer 1

Hint: Insulin is released from the pancreas from islets of Langerhans. Diabetes can be controlled by insulin as insulin helps to control the blood sugar level and let the excess glucose stored as glycogen. So insulin signals the liver to store blood sugars for later use.

Complete step-by-step anwer:
Previously insulin was taken from the pancreas of dead cattle and pigs but It caused allergic reactions in the patients and some showed other immune responses as its origin was foreign. And thousands of pigs were killed to get a small amount of insulin. Now it was also a challenge to complete the increasing needs for insulin and its production on a large scale.

Then recombinant DNA technology came into the picture. Now insulin was produced with the help of recombinant DNA technology and it proved very beneficial. Also, it was the first recombinant medicine to be used in the USA. The company which made it for the first time is named Eli lily. Genes that code for A and B peptides of the insulin was put into the plasmid of E.coli strains. Both chains were produced separately and further joined by disulfide linkages.
Hence the correct answer is option c.





Note: Insulin has many other functions in spite of controlling blood sugar levels. Insulin also manages the breakdown of protein and lipids due to changes in the fat cells. In the absence of insulin uptake of amino acids and potassium into the cells cannot take place. It also manages the excretion of sodium and fluid volume in urine. It also enhances the memory and learning capabilities of the brain.