Question

Restriction endonucleases are enzymes those which

• A. break phosphodiester bond within the DNA molecule
  
• B. remove nucleotides from the end of DNA
  
• C. break non-covalent bonds within the DNA
  
• D. are a class of DNA polymerases with restriction action
  

Answer 1

The correct option is A break phosphodiester bond within the DNA molecule


Restriction endonucleases are enzymes which recognize specific nucleotide sequences in a DNA molecule, often a palindrome, known as the restriction site, and cleave the phosphodiester bond (covalent bond) in the DNA at a specific nucleotide within the restriction site.

Enzymes which remove nucleotides from the end of DNA are termed exonucleases.