Advertisements
Advertisements
Question
Explain briefly:
Restriction enzymes and DNA
Advertisements
Solution
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.
APPEARS IN
RELATED QUESTIONS
Explain with the help of a suitable example the naming of a restriction endonuclease.
Name and describe the technique that helps in separating the DNA fragments formed by the use of restriction endonuclease
Collect 5 examples of palindromic DNA sequences. Better try to create a palindromic sequence by following base-pair rules.
Answer the following question.
Explain the significance of palindromic nucleotide sequence in the formation of recombinant DNA.
Answer the following question.
Write the use of restriction endonuclease in the formation of recombinant DNA.
Give a reason why :
Single cloning site is preferred in a vector.
Which of the following radioisotope is not suitable for DNA labeling based studies?
Molecular scissors, which cut DNA at specific site is ______.
'Restriction' in restriction enzyme refers to
A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is ______
Which of the following statements does not hold true for restriction enzyme?
Restriction enzymes that are used in the construction of recombinant DNA are endonucleases which cut the DNA at ‘specific-recognition sequence’. What would be the disadvantage if they do not cut the DNA at specific-recognition sequence?
How does one visualise DNA on an agarose gel?
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?
State the importance of elution in this process.
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.
State the principle involved in separation of DNA fragments using gel electrophoresis.
Identify the activity of endonuclease and exonuclease in the given image.
Which of the following was the very first restriction endonuclease to be isolated and characterized?
How do exonucleases differ fundamentally from endonucleases in their enzymatic site of action?
Why is it mandatory to cut both the vector DNA and the foreign source DNA with the exact same restriction enzyme when constructing recombinant DNA?
How are separated DNA bands visualized following agarose gel electrophoresis?
What is the process called when desired, separated DNA bands are physically cut out from the agarose gel and extracted from the gel piece?
