Tag: zoology

Questions Related to zoology

Which of the following statements regarding the structure of proinsulin and mature insulin are not correct?
(i) Proinsulin is made up of three polypeptide chains A, B, and C.
(ii) C-polypeptide chain with 33 amino acids is removed prior to insulin formation.
(iii) Mature insulin is made up of 51 amino acids and arranged in two polypeptide chains-A and B.
(iv) Polypeptide chain A has 30 amino acids and polypeptide chain B has 21 amino acids.
(v) Polypeptide chains A and B are interconnected by only one S-S linkage.

  1. (i) and (ii)

  2. (iii) and (iv)

  3. (iv) and (v)

  4. (iii), (iv) and (v)


Correct Option: C
Explanation:
Human insulin is made up of 51 amino acids arranged in two polypeptide chains: A, having 21 amino acids and B, with 30 amino acids. The two polypeptide chains are interconnected by two disulphide bridges. The two polypeptide chains are interconnected by two disulphide briges. The hormone develops from a storage product called pronsulin. Proinsulin has three chains: A, B and C, C-chain with 33 amino acids is removed prior to insulin formation.
So, the correct answer is '(iv) and (v)'.

Insulin is a/an.

  1. Polysaccharide

  2. Protein

  3. Amino acid derivative

  4. Lipid


Correct Option: B
Explanation:

Insulin is a large popylpeptide hormone and is insoluble in lipids, therefore, it cannot enter the target cell. It acts at the cell surface. It operates through extracellular membrane bound receptor, a heterotetrameric protein (extrinsic protein) on the target cell.

Human insulin is being commercially produced from a transgenic species of 

  1. Mycobacterium

  2. Rhizobium

  3. Saccharomyces

  4. Escherichia


Correct Option: D
Explanation:

In 1983, Eli Lilly an American company, first prepared two DNA sequences corresponding to A and B chains of human insulin and introduced them in plasmids of Escherichia coil to produce insulin and chains. Chains A and B were produced separately, extracted and combined by creating disulphide bonds to form human insulin (humulin).

__________ is a globular protein of $\sim 6\, kDa$ consisting of $51$ amino acids, arranged in $2$ polypeptide chains held together by disulphide bridge.

  1. Insulin

  2. Keratin

  3. Glucagon

  4. Fibrinogen


Correct Option: A
Explanation:
Insulin is composed of two peptide chains referred to as the A chain and B chain. A and B chains are linked together by two disulfide bonds, and an additional disulfide is formed within the A chain. In most species, the A chain consists of 21 amino acids and the B chain of 30 amino acids.

Although the amino acid sequence of insulin varies among species, certain segments of the molecule are highly conserved, including the positions of the three disulfide bonds, both ends of the A chain and the C-terminal residues of the B chain. These similarities in the amino acid sequence of insulin lead to a three dimensional conformation of insulin that is very similar among species, and insulin from one animal is very likely biologically active in other species. Indeed, pig insulin has been widely used to treat human patients.

So the correct option is 'Insulin'.

Pick up correct matching set of scientists in field of biotechnology.

   List I    List II
 A  Cohen  1  Structure of insulin
 B  Sharpey-Schafer  2  Biofuel cells
 C  F. Sanger  3  Established bacterial gene banks
 D  V. B. D. Skermman  4  Totipotency in plants
     5  Coined insulin
  1. A- 2, B- 5, C- 1, D- 3

  2. A- 3, B- 5, C- 1, D- 4

  3. A- 3, B- 5, C- 1, D- 2

  4. A- 2, B- 1, C- 5, D- 3


Correct Option: A
Explanation:
A biofuel uses living organisms to produce electricity. Biofuel cell is the cell that uses the enzymatic reaction to produce electricity. It was given by the Cohen in 1931.
Sir Edward Albert Sharpey-Schafer was an English physiologist.
He is regarded as a founder of endocrinology. Schafer coined the word "insulin" after theorising that a single substance from the pancreas was responsible for diabetes mellitus.
The Nobel Prize in Chemistry 1958 was awarded to Frederick Sanger "for his work on the structure of proteins, especially that of insulin".
V.B.D. Skermman established bacterial gene banks.
Thus, the correct answer is option A.

One important achievement of genetic engineering has been the production of

  1. Interferon

  2. Human insulin

  3. Cephalosporin

  4. Vinoblastine


Correct Option: B
Explanation:

Genetic engineering, also called as genetic modification, is the direct manipulation of an organism's genome using biotechnology. Human insulin is the name which describes synthetic insulin which is laboratory grown to mimic the insulin in humans. Human insulin is laboratory created by growing insulin proteins within E. coli bacteria (Escherichia coli). In the production of human insulin by bacteria, the human insulin gene is incorporated into the genetic material of these microorganisms. The mutant bacteria multiply forming lineages of insulin-producing bacteria. 

The first hormone artificially produced by culturing bacteria is

  1. Insulin

  2. Thyroxine

  3. Testosterone

  4. Adrenalin


Correct Option: A
Explanation:

Human insulin is the synthetic insulin which is grown in the laboratories. Human insulin is laboratory created by growing insulin proteins within E.coli bacteria (Escherichia coli). The newly constructed plasmids containing the transplanted genetic material are introduced into a benign E. coli bacterial strain. Once inside the bacteria, the genes are activated by the bacteria to form the protein chains found in insulin

So, the correct answer is 'Insulin'

Genetically engineered bacteria have been used in the commercial production of 

  1. Thyroxine

  2. Testosterone

  3. Human insulin

  4. Melatonin


Correct Option: C

Genetically engineered bacteria have been used in commercial production of

  1. Thyroxin

  2. Testosterone

  3. Human insulin

  4. Melatonin


Correct Option: C
Explanation:

In the 1980s, researchers used genetic engineering to manufacture a human insulin. In 1982, the Eli Lilly Corporation produced a human insulin that became the first approved genetically engineered pharmaceutical product. Human insulin is grown in the lab inside common bacteria. Escherichia coli is by far the most widely used type of bacterium used. Synthesizing human insulin is a multi-step biochemical process that depends on basic recombinant DNA techniques and an understanding of the insulin gene. DNA carries the small segment of the DNA, the insulin gene, which codes for the protein insulin. Manufacturers manipulate the biological precursor to insulin so that it grows inside simple bacteria.

Cyanogen bromide is employed in ____________.

  1. Genetic finger printing

  2. Tissue culture

  3. Synthesis of humulin

  4. Hybridoma technology


Correct Option: C