Question

Enzymes that recognize and cleave specific 4 to 8 base pair sequences of DNA are
A.DNA ligase
B. helicases
C. restriction endonucleases
D. DNA gyrase

Answer 1

Restriction endonucleases are the enzymes that recognize and cleave specific 4 to 8 base pair sequences of DNA.

• DNA ligases are the enzymes that use ATP to join nucleotides by phosphodiester bond and seal the single-strand break in a DNA molecule.
• Helicases are the enzymes that open up the DNA helix by unwinding it, which makes double-stranded DNA into single-stranded which acts as a template for DNA replication.
• DNA gyrases are those enzymes, which use ATP, to aid the unwinding of DNA by negative supercoiling of DNA helix.
• Restriction endonucleases are those nucleases, which cuts the nucleotide within a DNA molecule. These enzymes recognize their specific 4-8 base pair palindromic sequence and cleave the sequence from the double-stranded DNA strand. These enzymes act as molecular scissors in recombinant DNA technology.