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Questions
Distinguish between exonuclease and endonuclease.
Differentiate between exonuclease and endonuclease.
Discuss with your teacher and find out how to distinguish between exonuclease and endonuclease.
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Solution 1
| Sr. No. | Exonuclease | Endonuclease |
| 1. | It is a type of restriction enzyme that removes the nucleotide from the 5' or 3' ends of the DNA molecule. | It is a type of restriction enzyme that makes a cut within the DNA at a specific site to generate sticky ends. |
| 2. | They separated DNA base pairs at their terminal ends. |
They separate DNA at any location other than the terminal ends. |
| 3. | They work on single strands of DNA or gaps in double-stranded DNA. | They cut one or both strands of double-stranded DNA. |
Solution 2
| Feature | Exonuclease | Endonuclease |
| Clevage Site: | Eliminates nucleotides from DNA/RNA ends. | Cuts DNA within the strand at specific sites. |
| Requirement of Free Ends: | Needs free 3' or 5' ends (in one duplex strand). | Requires just one or both strands of the DNA duplex and doesn’t require free ends. |
| Mode of Action: | Progressively removes nucleotides one by one. | Cuts at specific recognition sequences. |
| Example: | DNA polymerase I (has exonuclease activity). | EcoRI, HindIII, BamHI (restriction enzymes). |
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