NEET BIOLOGY

Detailed explanation-1: -When a restriction endonuclease recognizes a sequence, it snips through the DNA molecule by catalyzing the hydrolysis (splitting of a chemical bond by addition of a water molecule) of the bond between adjacent nucleotides.

Detailed explanation-2: -In the laboratory, restriction enzymes (or restriction endonucleases) are used to cut DNA into smaller fragments. The cuts are always made at specific nucleotide sequences. Different restriction enzymes recognise and cut different DNA sequences.

Detailed explanation-3: -Restriction enzymes can cut the strands of DNA a little away from the centre of the palindrome sites, but between the same two bases on the opposite strands. This leaves single stranded portions at the ends. There are overhanging stretches called sticky ends on each strand.

Detailed explanation-4: -Restriction Enzyme Types Generally, Type I enzymes cut DNA at locations distant to the recognition sequence; Type II cut DNA within or close to the recognition sequence; Type III cut DNA near recognition sequences; and Type IV cleave methylated DNA.

Detailed explanation-5: -A restriction enzyme is a protein isolated from bacteria that cleaves DNA sequences at sequence-specific sites, producing DNA fragments with a known sequence at each end. The use of restriction enzymes is critical to certain laboratory methods, including recombinant DNA technology and genetic engineering.