AP BIOLOGY

Detailed explanation-1: -Restriction enzymes cut DNA bonds between 3′ OH of one nucleotide and 5′ phosphate of the next one at the specific restriction site. Adding methyl groups to certain bases at the recognition sites on the bacterial DNA blocks the restriction enzyme to bind and protects the bacterial DNA from being cut by themselves.

Detailed explanation-2: -Restriction enzymes, found naturally in bacteria, can be used to cut DNA fragments at specific sequences, while another enzyme, DNA ligase, can attach or rejoin DNA fragments with complementary ends.

Detailed explanation-3: -How do restriction enzymes work? Like all enzymes, a restriction enzyme works by shape-to-shape matching. When it comes into contact with a DNA sequence with a shape that matches a part of the enzyme, called the recognition site, it wraps around the DNA and causes a break in both strands of the DNA molecule.