Tag: biochemical techniques

Quizzes (6) Questions (139)

Questions Related to biochemical techniques

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

  1. distillation

  2. crystallisation

  3. distillation with reduced pressure

  4. steam distillation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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

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

Glycerin can be purified by:

  1. vacuum distillation

  2. simple distillation

  3. steam distillation

  4. fractional distillation
Reveal answer Fill a bubble to check yourself
A Correct answer
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.
Multiple choice chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

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

  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.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Distillation under reduced pressure lowers the boiling point of a liquid, which prevents the thermal decomposition of substances that are heat-sensitive. This technique is essential for liquids with high boiling points that would otherwise break down before reaching their boiling point at atmospheric pressure.

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

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?

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

Gel electrophoresis is used for

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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' .

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

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.

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.