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प्रश्न
Explain briefly:
Restriction enzymes and DNA
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उत्तर
Restriction enzymes belong to a larger class of enzymes called nucleases. They are mainly classified into two types:
- Exonucleases: They remove nucleotides from the terminal ends of the DNA molecule.
- Endonucleases: They make cuts at specific positions anywhere within the DNA molecule.
Restriction endonucleases are a specific class of endonucleases that recognise palindromic nucleotide sequences and cleave DNA at specific sites. They cut both strands of the DNA double helix at specific points to generate sticky or blunt ends, which are essential for creating recombinant DNA.
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संबंधित प्रश्न
Explain with the help of a suitable example the naming of a restriction endonuclease.
Name the enzymes that are used for the isolation of DNA from bacterial and fungal cells for recombinant DNA technology.
How does a restriction nuclease function? Explain
Name and describe the technique that helps in separating the DNA fragments formed by the use of restriction endonuclease
Make a chart (with diagrammatic representation) showing a restriction enzyme, the substrate DNA on which it acts, the site at which it cuts DNA and the product it produces.
Collect 5 examples of palindromic DNA sequences. Better try to create a palindromic sequence by following base-pair rules.
Distinguish between exonuclease and endonuclease.
Answer the following question.
Write the use of restriction endonuclease in the formation of recombinant DNA.
Which of the following radioisotope is not suitable for DNA labeling based studies?
Restriction enzymes ______.
There is a restriction endonudease called as EcoRI. What does co part in it stands for?
Molecular scissors, which cut DNA at specific site is ______.
'Restriction' in restriction enzyme refers to
DNA fragments separate according to size through?
Which of the given statements is correct in the context of visualizing DNA molecules separated by agarose gel electrophoresis?
What does H in’ ‘d’ and ‘III’ refer to in the enzyme Hind III?
A plasmid DNA and a linear DNA (both are of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis, plasmid shows one DNA band while linear DNA shows two fragments. Explain.
CTTAAG
GAATTC
- What are such sequences called? Name the enzyme used that recognizes such nucleotide sequences.
- What is their significance in biotechnology?
Carefully observe the given picture. A mixture of DNA with fragments ranging from 200 base pairs to 2500 base pairs was electrophoresed on agarose gel with the following arrangement.
(a) What result will be obtained on staining with ethidium bromide? Explain with reason.
(b) The above setup was modified and a band with 250 base pairs was obtained at X.
What change(s) were made to the previous design to obtain a band at X? Why did the band appear at position X?
What is elution?
Given below is the restriction site of a restriction endonuclease Pst-I and the cleavage sites on a DNA molecule.
\[\ce{5' C - T - G - C - A \overset{\downarrow}{-}{G 3'}}\]
\[\ce{3' G\underset{\uparrow}{-} A - C - G - T - C 5'}\]
Choose the option that gives the correct resultant fragments by the action of the enzyme Pst-I.
'EcoRI' has played a very significant role in rDNA technology.
- Explain the convention for naming EcoRI.
- Write the recognition site and the cleavage sites of this restriction endonuclease.
What are the protruding and hanging stretches of DNA produced by these restriction enzymes called? Describe their role in the formation of rDNA.
State the principle involved in separation of DNA fragments using gel electrophoresis.
Hind II always cuts DNA molecules at a particular point called recognition sequence and it consists of ______.
