Tag: biochemical techniques

Questions Related to biochemical techniques

The fragrance of the flower is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in the vapour phase. A suitable method for the extraction of these oil from the flower is:

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. distillation

  2. crystallisation

  3. distillation with reduced pressure

  4. steam distillation

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Correct Option: D
Explanation:

As the component is miscible with water vapour in vapour phase so steam distillation will be most suitable method for extraction.

Glycerin can be purified by:

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. vacuum distillation

  2. simple distillation

  3. steam distillation

  4. fractional distillation

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Correct Option: A
Explanation:
The liquids which decompose at its boiling point can be purified by vacuum distillation. Glycerol decomposes at its boiling point (563K). It can be distilled by vacuum distillation without decomposition at 453K and under 12mm Hg pressure.

Distillation under reduced pressure is generally used to purify those liquid which:

chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

  1. have very low boiling points

  2. are volatile

  3. have high boiling points and which decompose below their boiling points

  4. have a large difference in their boiling points.

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Correct Option: C

Having become an expert on gel electrophoresis, you are asked to examine a gel for a colleague. Where would you find the smallest segments of DNA?

bio-chemistry biochemical techniques manipulation of dna electrophoresis isolation and separation of dna

  1. Near the positive electrode, farthest away from the wells

  2. Near the negative electrode, close to the wells

  3. Near the negative electrode, farthest away from the wells

  4. Near the middle, they tend to slow down after the first few minutes

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Correct Option: A
Explanation:

Since DNA is itself negatively charged, it would move towards the positive electrode. In gel electrophoresis, DNA fragments are separated on the basis of charge and masses. Thus, smaller the DNA fragment farther it moves from the well.

So, the correct option is A.

Gel electrophoresis is used for

bio-chemistry biochemical techniques manipulation of dna electrophoresis isolation and separation of dna

  1. Construction of recombinant DNA by joining with cloning vectors

  2. Isolation of DNA molecules

  3. Cutting of DNA into fragments

  4. Separation of DNA fragments according to their size

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Correct Option: D
Explanation:

Gel electrophoresis is used to separate macromolecules like DNA, RNA and proteins. DNA fragments are separated according to their size. 

So, the correct option is 'Option D' .

Select the correct option to fill up the blanks.


(i) _____ is a natural polymer extracted from ______.

(ii) The DNA fragments purified by gel electrophoresis are used in constructing _____ by joining them with ______.
(iii) The ligation of alien DNA is carried out at a _____ present in one of the two ____ in a plasmid vector.
(iv) _____ enzyme remains active during the high temperature-induced denaturation of ds DNA. DNA fragments are resolved according to their ______
(v) through _____ in agarose gel electrophoresis.

bio-chemistry biochemical techniques manipulation of dna electrophoresis isolation and separation of dna

  1. (i) Agarose, seaweeds (ii) recombinant DNA, cloning vector (iii) restriction site, antibiotic resistance genes (iv) Taq polymerase, size(v) sieving effect.

  2. (i) Agarose, sea weeds (ii) Restriction site, antibiotic resistance genes (iii) recombinant DNA, cloning vector (iv) Taq polymerase (v) size, sieving effect

  3. (i) Agarose, sea weeds (ii) restriction site, antibiotic resistance genes (iii A-DNA, cloning vector (iv) Taq polymerase (v) size, sieving effect

  4. (i) Size, sieving effect (ii) agarose, sea weeds (iii) recombinant DNA, cloning vector (iv) Taq polymerase (v) restriction site, antibiotic resistance genes

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Correct Option: A
Explanation:

Agarose is a natural polymer extracted from sea weeds. The DNA fragments purified by gel electrophoresis are used in constructing recombinant DNA by joining them with the cloning vector. The ligation of alien DNA is carried out at a restriction site present in one of the two antibiotic resistance genes in a plasmid vector. Taq polymerase enzyme remains active during the high temperature-induced denaturation of dsDNA.  DNA fragments are resolved according to their size through a sieving effect in agarose gel electrophoresis.

So, the correct option is 'Option A'.

Anticodon that aligns with initiator codon is

bio-chemistry biochemical techniques manipulation of dna electrophoresis isolation and separation of dna

  1. 5' - UAC - 3'

  2. 5 - UCA -3'

  3. 3' UAC - 5

  4. 3 CAU 5

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Correct Option: C

Which of the following does not produce sticky ends?

bio-chemistry biochemical techniques manipulation of dna electrophoresis isolation and separation of dna

  1. Sma I

  2. EcoRI

  3. SalI

  4. BamHI

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Correct Option: A

Which one of the following methods requires two genetically variable individuals to produce the progeny?

bio-chemistry biochemical techniques manipulation of dna electrophoresis isolation and separation of dna

  1. Cutting

  2. Layering

  3. Budding

  4. Goatee

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Correct Option: A