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प्रश्न
How does a restriction nuclease function? Explain
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उत्तर
Restriction endonuclease functions by recognising its specific sequence. It binds to the DNA and cuts each to the two strands of the double helix at specific points in their sugar phosphate backbones. These enzymes cut the strand of DNA between the same two bases on the opposite strands leaving a single-stranded portion at their ends. These overhanging stretches are called sticky ends on each strand. The enzyme DNA ligase functions depending on the stickiness of these ends. For example, the restriction endonuclease EcoRI found in the colon bacteria E. coli recognises the base sequence GAATTC in the DNA duplex and cuts its strands between G and A.
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संबंधित प्रश्न
How does restriction endonuclease function?
Answer the following question.
Write the use of restriction endonuclease in the formation of recombinant DNA.
Which of the given statements is correct in the context of visualizing DNA molecules separated by agarose gel electrophoresis?
While isolating DNA from bacteria, which of the following enzymes is not required?
What does H in’ ‘d’ and ‘III’ refer to in the enzyme Hind III?
A mixture of fragmented DNA was electrophoresed in an agarose gel. After staining the gel with ethidium bromide, no DNA bands were observed. What could be the reason?
CTTAAG
GAATTC
- What are such sequences called? Name the enzyme used that recognizes such nucleotide sequences.
- What is their significance in biotechnology?
Given below is the stepwise schematic representation of the process of electrophoresis. Identify the 'alphabets' representing
- Anode end
- smallest/lightest DNA strand in the matrix
- Agarose gel
State the principle involved in separation of DNA fragments using gel electrophoresis.
Identify the activity of endonuclease and exonuclease in the given image.
